Multiple fanless power supplies?

[RIchardF]

I am wondering if it's possible to power the GPUs' PCIe via one fanless power supply and the CPU, motherboard, fans, and so forth with another?

I realize that GPUs draw something like 75 watts from the motherboard. So, if you have two GPUs that's 150 watts. With a 125 watt CPU that's 275 watts. That still leaves power left over for fans and other things. However, if the additional power from PCIe connectors could be delivered by a second fanless power supply, then the problem of having a multi-GPU setup that's quiet is helped quite a bit. The only power supply I've read about that's pretty quiet at high wattage is the Corsair RM 850 and it has reliability questions. Plus, two fanless power supplies will be quieter even than it.

I've read that people once used a separate power supply for GPUs but that was quite a long time ago. It seems like there is still a reason to do it today, since fanless supplies seem to max around 520 watts.

I am thinking of building a 1080mm or 2x 1080mm watercooling setup with 2 GPUs (most likely 970s). I want it to be as noiseless as possible. Computer fan noise causes my ears to ring for some reason, even fan noise many would consider quiet. Plus, I like to listen to classical music a lot and don't want the fans to interfere. I can hear my dehumidifier that's in the basement across my condo two floors up, so I have to say I have rather sensitive hearing.

Is there a way I can use two power supplies like this?

[bastiaan]

I am wondering if it's possible to power the GPUs' PCIe via one fanless power supply and the CPU, motherboard, fans, and so forth with another?

There's nothing patently impossible about that. You'll have to rig one of the PSUs to start up without an ATX connector, but it's not difficult.

I realize that GPUs draw something like 75 watts from the motherboard. So, if you have two GPUs that's 150 watts. With a 125 watt CPU that's 275 watts.

The only power supply I've read about that's pretty quiet at high wattage is the Corsair RM 850 and it has reliability questions.

I don't see quite why you would power a max 275 Watt build with an 850W PSU though. I can't imagine 'high wattage' refers to a 300W load in a 850W PSU.

Plus, two fanless power supplies will be quieter even than it.

Probably, but you're going to need decent fan cooling in your case because you can't rely on the PSU to move the heat out of the case. I think SPCR does not generally recommend fanless PSUs, because these days there are ample good quality PSUs available that also have really quiet fans.

Why don't you get yourself a good quality 400-500W PSU with a quiet fan instead? How about the Be Quiet Straight Power 10 500W, or the Enermax Platimax 500 Watt, for instance?

[edh]

It's a really bad idea. There have been attempts before on other parts of the Internet to run 2 PSUs and it is an extremely bad idea. As has been pointed out, you need both PSUs to start up together. What then happens if one PSU goes off and the other carries on supplying power? Or if one PSU has an earth fault and the other doesn't and a shock takes the path of least resistance to earth... through all of your components.

In terms of power envelope, just how much are you expecting to use? You can get a 600W fanless PSU which is enough for anything that matters. Most likely if we study the configuration you are planning on building and what you plan to use it for (details please), we'll find that the power draw is less than you expect.

Next reason why it's bad: Efficiency is worse than with a single larger sized PSU. Conversion is always more efficient on a larger scale so doubling up a smaller sized PSU will waste more electricity, giving more heat. Plus they'll be more expensive.

Finally: Just what kind of system do you expect to be building that would use over 600W in which a high efficiency, fan cooled PSU is not going to be drowned out by the rest of the system? Cooling the 50W of waste heat in the PSU quietly is going to be irrelevant compared to the 600W cooling requirements of the rest of the system.

[RIchardF]

Thanks for the responses.

Here is an example build that seems as if it would necessitate a second power supply if I were to go with a fanless system:

5820K overclocked near stock voltage = 200-250 watts? (Unfortunately, overclocking review sites always go for excessive voltage. My opinion is that overclocking should be limited to near stock, to maintain reasonable performance per watt and lessen the chance of damaging the chip.)

Two GTX 970s. 360 - 500 watts (Tom's Hardware found the Gigabyte Windforce 970s peaked at over 240 watts, due to factory overclocking, while a reference 980 only drew 177 (354 watts for two). I would prefer to have the much more power efficient reference 980s but I don't think my budget will allow going over 970s. Plus, given the limited VRAM in the 980 that card seems like a bad deal unless you're going to stick with just one.

So, with 250 watts for a lightly overclocked 5820K and 500 watts for factory overclocked 970s I'm looking at 750 watts, plus the wattage needed to run a watercooling pump, motherboard + RAM, many fans at very low speeds (thinking about 4x 180mm or 9x 120mm per 1080mm radiator), and SSDs (no mechanical hard disks).

One person built an external dual 1080mm radiator system to cool his heavily overclocked 45nm i7 950 and AMD AMD R9-290. He used 18 Noctua 120mm fans running at very low speeds (limited to 500 RPM) plus 5 of them as case fans. He said the system remains silent at full load. I was planning to use a single 1080mm radiator with either 4 180mm fans or 9 120mm fans but he said just one of the radiators was not enough to get the fan RPMs down enough for "silence".

Unfortunately, he didn't provide any decibel measurements, so I'm not sure what his idea of silence is. I have read a number of times that watercooling pumps can be a significant noise source, so I've tried to discover which one will be quiet enough but also have enough performance to feed two large external radiators.

I've also heard that the 180mm fans on the market tend to be noisy, but I'm not sure of 4 of them would still be more efficient in terms of noise-cooling ratio (targeting quiet over performance) than 9 120mm fans. I don't want to waste money on overkill (I have no interest in showing off my system to anyone) but I also want quiet, regardless of what the system is doing. I am not the sort of person who is fine with a noisy system when it's being used heavily. I don't play fast twitch FPS games but I want smooth framerates at 1440p in any game I throw at the system for several years. I have no interest in moving to 4K.

I didn't know that 600 watt fanless power supplies are now available. However, every "quiet" power supply that I've read reviews for seems to become not very quiet when loaded at 60-90%. The Seasonic SS 1050, for instance, was said to be able to be heard "rooms away" by Anandtech and produces 50+ decibels. I would rather spend more money and lose a bit of efficiency to have a truly silent PSU when my system is fully loaded. However, your warnings about dangerous problems with the power being supplied may mean the two fanless PSU idea won't work at all.

I could save power by going with an i7 4970K and single GTX 980, but the extra $50 at Microcenter for the 5820K seems like it may be worth it, as six cores should help to provide smoother game play and better performance for other tasks like video encoding. Rumor has it that Haswell-E motherboards will be able to support Skylake chips, which could be a major benefit for getting a Haswell-E platform. The limitation of just having 24 PCIe lanes is a question, though. If GPUs become much more powerful in the next generation I don't want the PCIe slots' speed caps to be a significant drawback. The 5830K has 40 PCIe lanes. The issue of microstutter stemming from the use of dual GPUs is also something to consider. Nvidia's G-sync is supposed to eliminate that, but I don't have a monitor that supports G-sync and I can't replace the monitor because it's new and there is nothing with G-sync that has similar performance specs (BL3200PT).

The performance of the thinner 1080mm radiator at low fan speed is equivalent to the 60mm model, although I'm not sure if the flow rate would be an issue with two of them. The guy with the Noctua setup I linked to has one of the thinner profile (45mm I think) and one of the 60mm. It may be more sensible to get a 600 watt fanless power supply and stick with one of the radiators, the 4790K, and the single GTX 980. However, I don't like paying the premium for the 980 since it has just 4 GB of VRAM and the 4790K motherboard won't support Skylake chips. DDR4 is also set to improve in terms of performance to latency ratio as time moves forward. It should eventually be a true improvement, especially with quad channel addressing.

[RIchardF]

It's a really bad idea. There have been attempts before on other parts of the Internet to run 2 PSUs and it is an extremely bad idea. As has been pointed out, you need both PSUs to start up together. What then happens if one PSU goes off and the other carries on supplying power? Or if one PSU has an earth fault and the other doesn't and a shock takes the path of least resistance to earth... through all of your components.

What about this? http://www.add2psu.com/

It has good reviews on Amazon.

[xan_user]

why are you trying to get a fanless PSU? the fans on 2 video cards will be louder than a decent fanned PSU...

[RIchardF]

why are you trying to get a fanless PSU? the fans on 2 video cards will be louder than a decent fanned PSU...

The system would be watercooled with 2 1080mm external radiators. That does include the graphics cards. I'm not interested in the old "something else in the system will mask the PSU noise" rationalization. The entire reason for me being willing to mess around with water in the first place is to deal with GPU noise. I'd much rather not have to bother with it but I see no other way to provide that much surface area for cooling without high RPM fans.

The ATX GPU form factor is very anachronistic. The usually hottest components in a PC shouldn't have the smallest fans for cooling, fans that aren't even efficiently exhausting waste heat. I actually find it quite bizarre that nothing has been done to fix the issue beyond exotic watercooling DIY or a poor hodgepodge of multiple AIO units which is the current emerging trend.

[xan_user]

timeless isnt old.

so, external radiator fan and pump noise.

don quixote keeps coming to mind.

[RIchardF]

timeless isnt old.

so, external radiator fan and pump noise.

don quixote keeps coming to mind.

That's not a very productive bit of input. If you have a better suggestion, though, I am all ears.

The guy with the Noctua build has a partition between him and the radiators. It is possible to build an enclosure as well. Even the largest premade cases only have enough room for one comparatively small radiator at the top. People resort to putting additional radiators on the front and bottom which causes heat to be pushed into their cases — not very efficient.

I wonder what Don would think about silent Seasonic power supplies that can be heard "rooms away".

Anandtech: ... the 120mm fan can be clearly heard at just 40% load and its speed climbs rapidly as the load increases, surpassing even 50dB(A) at very high loads. At such noise levels, the Platinum SS-1050XP3 can be clearly heard from rooms away.

[xan_user]

my only suggestion, is to use one fanned PSU. . and then enjoy the pump and radiator fan noise.

[RIchardF]

my only suggestion, is to use one fanned PSU. . and then enjoy the pump and radiator fan noise.

If your only purpose here is to be rude and unproductive I suggest that you move on.

[edh]

5820K overclocked near stock voltage = 200-250 watts?

Far less than that number in the real world. Plus, what exactly do you plan on doing that requires you to have a 5820K? It's well accepted that more and more cores doesn't improve gaming performance as they are not well multithreaded. Even a quad core is superfluous. If you are building a system for games, save a whole load of money and buy an i5.

Two GTX 970s.

SLI is poor value. The money you're spending on the second card down the line would be better off spent on replacing the one card that you have with a newer, faster, more energy efficient card. You'd be better off buying a single GTX 980 if a GTX 970 is not fast enough on it's own. Far easier to keep a single card cool than multiple cards.

Gigabyte Windforce 970s peaked at over 240 watts, due to factory overclocking, while a reference 980 only drew 177 (354 watts for two). I would prefer to have the much more power efficient reference 980s

Those numbers don't make sense. The GTX 980 definitely uses more power than a GTX 970. Marginally more enerfy effiicent if you look at FLOPS/WATT but it does use more power. Also be very careful how different numbers are measured. You simply can't compare if the system is not identical and have they measured from the wall in which case you need to take off the efficiency losses of the PSU.

http://linustechtips.com/main/topic/682 ... completed/

That is NOT going to be SPCR quiet even if they are running at only 500rpm. Amazing to see that this guy has 18 fans right beside his bed! It does also lead me to question the guys priorities as he has spent all of that money on his computer yet doesn't have a proper space to put it in so it's in his bedroom. Maybe if he had not spent so much money on his computer he could have moved to a bigger house. Or possibly out of his parents house?!?

I want smooth framerates at 1440p in any game I throw at the system for several years.

Buy for now. Don't futureproof. Futureproofing never works out the way you plan and in hindsight you always end up looking back and realising that you've wasted a load of money. It's one of the accepted things on SPCR forums.

my only suggestion, is to use one fanned PSU. . and then enjoy the pump and radiator fan noise.

If your only purpose here is to be rude and unproductive I suggest that you move on.

He has a very valid point. If you are trying to build a system that uses so much power, any decent PSU will be entirely drowned out by the noise made by the rest of the system. Water cooling is not silent. For low noise, watercooling is not as good as decent air coolers as you have the inherent vibration of the pumps. I really, really can't recommend you doing any of what you are planning on doing.

[xan_user]

Im sorry you dont agree, im just trying to save you from needlessly buying, and troubleshooting 2 PSU's.

Your setup will not have a more silent computer with 2 fanless PSU's.

Enjoy your build.

And I dont know where everyone else manners are;

WELCOME TO SPCR!!!!

I'm out.

[RIchardF]

Im sorry you dont agree, im just trying to save you from needlessly buying, and troubleshooting 2 PSU's.

Your setup will not have a more silent computer with 2 fanless PSU's.

Enjoy your build.

And I dont know where everyone else manners are;

WELCOME TO SPCR!!!!

I'm out.

You didn't even read my opening post (which made it quite clear that I was planning to use large radiators to cool GPUs with water rather than leaving GPU fan coolers attached) before replying with your "advice" about GPU fan noise , let alone the even more detailed follow-up post I wrote. Then you followed that up with the Don Quixote post. You're one to lecture anyone about forum manners.

Your setup will not have a more silent computer with 2 fanless PSU's.

That's not correct, unless there is an issue with electrical noise. Two fanless power supplies can't make more noise than a single power supply with a fan, unless they have coil whine or some other form of electrical noise. The issue of cooling them can be dealt with with various strategies that we could discuss if you were interested in discussion rather than provocation.

As I said, I have yet to see evidence of an actually silent single power supply that can provide high wattage. They all spin up. Reviewers invariably try to rationalize this with the comment that "some other part of the system will be louder anyway", as if that eliminates the additional noise contributed by the power supply. The closest thing I've found to a quiet high wattage PSU is the Corsair RM 850, which has pretty large heatsinks, but it has a poor reputation and still becomes quite audible anyway once it's loaded enough.

I had the idea of a double-length new form factor that I posted in another thread. Perhaps that could make it possible to increase the wattage of passive power supplies by providing more area for heat sinks or, with the use of two large fans, eliminate the issue of a high wattage power supply becoming noisy when loaded beyond 50%. At this point, though, such a PSU does not exist and cases aren't designed for that form factor. Therefore, the only solution I am left with is to use two passive power supplies. If you have a better idea then post it.

[RIchardF]

He has a very valid point. If you are trying to build a system that uses so much power, any decent PSU will be entirely drowned out by the noise made by the rest of the system.

That is not a valid point. Noise produced by other parts does not eliminate noise produced by the PSU. It's only a valid point if you don't read my posts which make it clear that I am doing everything possible to minimize the noise produced by other parts, like the GPUs. He was under the impression that I was going to use the GPU fans, which is not a very smart thing to do. Yes, it's impractical to worry a lot about PSU noise if you're going to retain horribly inefficient GPU coolers with their tiny fans pointing in unhelpful directions in terms of eliminating heat (or which, in the case of blowers, are so extremely tiny that even heat elimination out of the case can't outweigh the noisiness). Reading my posts would have been helpful.

The "other things will mask the PSU noise" is a red herring argument unless those parts can actually eliminate those decibels produced or, from a practical standpoint, someone isn't doing everything possible (within reason) to reduce the noise produced by other parts.

Water cooling is not silent. For low noise, watercooling is not as good as decent air coolers as you have the inherent vibration of the pumps.

Build a 750 watt rig with air cooling and a single fan PSU that is as quiet when loaded as one with two 1080mm radiators (or even one) and dual passive power supplies. If there is concrete proof that this is possible without an extremely expensive case like the old passive Zalman, then I will go that route. I will also be very grateful since I won't have to deal with the problems of water, like potential leakage, which I would prefer to not have to deal with. From the research I've conducted, though, I don't think such a system is possible with current existing components — sans exotic cases like that Zalman. Perhaps a PSU maker will one day make a double-sized high wattage passive (or truly quiet throughout its entire range) PSU.

[xan_user]

I did read this part;

I can hear my dehumidifier that's in the basement across my condo two floors up, so I have to say I have rather sensitive hearing.

good luck with the water cooling rig!

[RIchardF]

I did read this part;

I can hear my dehumidifier that's in the basement across my condo two floors up, so I have to say I have rather sensitive hearing.

good luck with the water cooling rig!

Not a single post of yours in this topic has been anything other than trolling. I am going to see if this site has an ignore list function.

[xan_user]

ucp.php?i=zebra&mode=foes

[CA_Steve]

A couple of comments. Tom's Hardware is looking at instananeous power draw in their gfx card articles. While it's correct to say the overclocked GTX 970's drew up to ~240W of instantaneous power from the mobo and PEG connectors, the reality is the PSU's fan controller is usually based on temperature rise and that's dependant on the average sustained power. Power loads fluctuate on one microsecond intervals, the fan probably responds in 100's of milliseconds. So, for PSU noise levels, you should base it on the expected sustained average power, which TH found to be ~190W for this particular OC'ed card.

CPU: The sweet spot continues to be an i5 for gaming, mostly because few games make use of hyperthreading or more than 4 physical cores. An overclocked Devil's Canyon i5 should work well. Get an i7 or a Haswell E 6 core if you want to speed up your video editing/transcoding. Let's say you overvolt an 84W TDP CPU and drive it up to 125W.

Power use: CPU + two GTX 970s + mobo/etc.. Stressed instantaneous load is 125W + 2* 240 + ~50W = 655W. Stressed ave load is 125W + 2*190 + 50 = 555W. Your gaming load might be closer to 500W. So, the question is: are there PSUs that will be quieter than your gfx card cooling solution while running at 500-560W load? Probably. You'll have a tough time getting two GTX 970s to be quieter than 17-20dB(A). Take a look at something like the be quiet Dark Power Pro 10 series.

[MikeC]

+1 for Steve's comments about instantaneous power vs longer term avg. Ditto any benefit of going to 5830K & attendant higher costs of motherboard & RAM. Stay with Steve' CPU recommendation & I agree that sustained power demand from the system during gaming would not go past 500W. Seasonic's new Snow Silent 1050W Platinum PSU with FDB fan may be a good bet to run fanless up to that kind of load.

Given what ASUS (and apparently MSI) have achieved with the acoustics of the GTX 980/970 card, I'd be inclined go with those cards, and get a motherboard with maximum separation between PCIe slots so that the card closest to the CPU doesn't get choked for airflow. Then assemble these in a Silverstone FT05 or FT02, with their 90 degree rotated motherboard position to minimize heat convection between GPUs and CPU. With the big bottom panel "standard" minimum speed (~700rpm), we measure ~25 dBA@1m, but you can probably afford to go slower for idle/low load, and (using whatever fan control suits you) allow the fans to ramp up gently as load increases. With a good tower CPU cooler, I doubt the SPL at load would actually exceed 25 dBA/1m. Generally, those big fans have a pretty benign broadband sound; I doubt you'd notice them in the middle of gaming.

You could also try the Fractal Design Define R5 which we used for our 2nd ATX gaming build guide. Its fans are much quieter than those in the Silverstone FT05 but the top GPU will definitely run hotter than the bottom one, which risks its cooling fans ramping up audibly; they will have the most prominent noise quality, due to their smaller size & higher RPMs . Watercooling just the top card with an AIO cooler like the NZXT G10 + Kraken X61 might be best; the acoustic penalty should modest.

[RIchardF]

A couple of comments. Tom's Hardware is looking at instananeous power draw in their gfx card articles. While it's correct to say the overclocked GTX 970's drew up to ~240W of instantaneous power from the mobo and PEG connectors, the reality is the PSU's fan controller is usually based on temperature rise and that's dependant on the average sustained power. Power loads fluctuate on one microsecond intervals, the fan probably responds in 100's of milliseconds. So, for PSU noise levels, you should base it on the expected sustained average power, which TH found to be ~190W for this particular OC'ed card.

CPU: The sweet spot continues to be an i5 for gaming, mostly because few games make use of hyperthreading or more than 4 physical cores. An overclocked Devil's Canyon i5 should work well. Get an i7 or a Haswell E 6 core if you want to speed up your video editing/transcoding. Let's say you overvolt an 84W TDP CPU and drive it up to 125W.

Power use: CPU + two GTX 970s + mobo/etc.. Stressed instantaneous load is 125W + 2* 240 + ~50W = 655W. Stressed ave load is 125W + 2*190 + 50 = 555W. Your gaming load might be closer to 500W. So, the question is: are there PSUs that will be quieter than your gfx card cooling solution while running at 500-560W load? Probably. You'll have a tough time getting two GTX 970s to be quieter than 17-20dB(A). Take a look at something like the be quiet Dark Power Pro 10 series.

Thank you for this response. I actually have been mulling that exact PSU for some time, along with the Corsair RM 750 and 850 models by Chicony. The Dark Power is a more advanced unit but it also has a bit smaller heatsinks and, being built on a Seasonic platform, is more aggressive about cooling than the Corsair. One review site said it rarely mentions PSU noise but the fan in the be quiet! was so loud at full load that it could be heard above the loud testing equipment. From what I've read it seems like the be quiet! PSU is quite nice until you pass a certain load level and then you're in for a bunch of noise. The Corsair 750 watt RM operated fanless until 450 watts in one chart I saw but went up to 1100 RPMs at max.

I'm not sure that either of those PSUs will manage a 560 watt load without significant fan noise. Plus, I have really been leaning toward the Haswell-E because I do quite a bit of video encoding, like the idea of not having to buy a motherboard again when Skylake hits, and like the idea of having quad channel DDR4 at high speeds available on the motherboard for feeding Skylake when it does hit.

Do you think it's possible (safe, especially) to use two fanless PSUs, perhaps with something like that unit I linked to? I have enough space where fitting something into a conventional case is not necessary. I also don't need portability. I can also hire my mother, who is very good at building things, to build me a custom enclosure if necessary.

I am also curious about your reaction to the idea of using two massive radiators with fans running at very very low RPMs, like that guy did with the Noctuas. Pump noise appears to be the main issue with that setup. I really don't know where to find good decibel comparisons between pumps. From searches with Google I can only find subjective comments that are pretty vague.

Part of the reason for building around a bit more wattage than peak maximum was also to provide a bit of headroom for future equipment upgrades. While I have no plans to go to a third GPU, it may be that the power consumption of the next generation of GPUs may be a bit higher. I tend to hold onto my equipment for a long time, but I may want to sell the 970s and replace them with 14/16nm parts that use more power despite the die shrinkage. There is also the issue of capacitor aging with PSUs.

+1 for Steve's comments about instantaneous power vs longer term avg.

Thank you for your comments also.

Yes, it's definitely a good point, but I was mainly using the max wattage to demonstrate a load that is outside of the capability of a single fanless PSU. I was told that there is a 600W passive PSU (although the most I have read about is 520), so my hypothetical build with 700+ peak watts exceeded that.

Ditto any benefit of going to 5830K & attendant higher costs of motherboard & RAM. Stay with Steve' CPU recommendation & I agree that sustained power demand from the system during gaming would not go past 500W. Seasonic's new Snow Silent 1050W Platinum PSU with FDB fan may be a good bet to run fanless up to that kind of load.

I'm surprised by the recommendation of a Seasonic. From what I've been seeing from reviews, Seasonic tends to be aggressive with fan speed to maintain very low internal PSU temperature. Their PSUs are outstanding in terms of regulation and ripple, but my first priority is noise.

Given what ASUS (and apparently MSI) have achieved with the acoustics of the GTX 980/970 card, I'd be inclined go with those cards, and get a motherboard with maximum separation between PCIe slots so that the card closest to the CPU doesn't get choked for airflow.

Using GPU fans is really going to be quieter than watercooling with massive radiators, like two 1080mm models? I understand that AIO watercooling and conventional in-case watercooling tends to be louder due to inefficient placement, limited surface area (which necessitates faster RPM fans and tighter radiator fins), and pump redundancy (such as having multiple AIOs). However, it seems like, by having very large horizontal surface area radiators with widely spaced fins, it should be possible to use minimal fan speed and, hopefully, low pump speed.

I am by no means a watercooling expert, though, so it may be that it's not possible to find any pump that's capable of pushing water through two of those radiators (even the 60mm models) at a quite quiet noise level.

While I definitely understand the advice of cutting back on the wattage of my equipment in order to achieve less noise, I am also quite curious about what might be accomplished, in terms of expanding the upper limit of wattage, by using such large radiators and the other strategies I mentioned (such as dual passive PSUs).

Then assemble these in a Silverstone FT05 or FT02, with their 90 degree rotated motherboard position to minimize heat convection between GPUs and CPU. With the big bottom panel "standard" minimum speed (~700rpm), we measure ~25 dBA@1m, but you can probably afford to go slower for idle/low load, and (using whatever fan control suits you) allow the fans to ramp up gently as load increases. With a good tower CPU cooler, I doubt the SPL at load would actually exceed 25 dBA/1m. Generally, those big fans have a pretty benign broadband sound; I doubt you'd notice them in the middle of gaming.

I have been seriously considering a Silverstone build for quite some time. It's the GPU noise and PSU noise that prompted me to consider the external watercooling solution. The Silverstone cases benefit most, from what I've read, from blower style GPU coolers, which are the loudest of all. The MSI cooler is fairly good, only apparently losing effectiveness with one of its heat pipes. However, I am still not convinced about the comparatively small fans on these dual fan units as well as their inefficient fan placement that expels heat into the case.

You could also try the Fractal Design Define R5 which we used for our 2nd ATX gaming build guide. Its fans are much quieter than those in the Silverstone FT05 but the top GPU will definitely run hotter than the bottom one, which risks its cooling fans ramping up audibly; they will have the most prominent noise quality, due to their smaller size & higher RPMs . Watercooling just the top card with an AIO cooler like the NZXT G10 + Kraken X61 might be best; the acoustic penalty should modest.

If one is going to go to the pump route with an AIO, why not use a pump instead to power massive external radiators? If the pump is mounted inside a quiet case and the radiators are run with very little fan RPM (the Noctua guy said 350 RPM as I recall) it seems to me that it might be better. Maybe not...

[RIchardF]

Far less than that number in the real world. Plus, what exactly do you plan on doing that requires you to have a 5820K? It's well accepted that more and more cores doesn't improve gaming performance as they are not well multithreaded. Even a quad core is superfluous. If you are building a system for games, save a whole load of money and buy an i5.

The system isn't just for gaming. It's just that gaming tends to be the thing that causes the most noise and uses the most wattage. I don't think a quad is superfluous. Gaming engines are beginning to require 4 threads to run smoothly at high settings. There are already some that run better on an i5 than on an i3. I want to be able to run games at maximum settings at 1440p with good minimum frame rates. Since I don't play fast twitch FPS games, I feel I can live without a minimum of 60 FPS. I am wondering if the microstutter from two 970s will be more bothersome than the slowdowns from using a single 980.

SLI is poor value. The money you're spending on the second card down the line would be better off spent on replacing the one card that you have with a newer, faster, more energy efficient card. You'd be better off buying a single GTX 980 if a GTX 970 is not fast enough on it's own. Far easier to keep a single card cool than multiple cards.

Minimum frame rates seem to be the biggest issue with single cards, from what I recall reading, though. The 980's price is also quite inflated due to it being the top card. I do like its greater efficiency, though, since it apparently draws fewer watts in reference form than overclocked 970s draw. It's also true that cooling one card is easier than cooling two, especially inside a case.

I don't want to invest money into this setup and have to reduce quality settings to avoid annoying stutter. If a single 980 can handle 1440p smoothly at max settings then I will strongly consider going the single GPU route and pay the premium for the 980. Not having G-sync may make the microstutter issue more prominent, from what I recall.

Those numbers don't make sense. The GTX 980 definitely uses more power than a GTX 970. Marginally more enerfy effiicent if you look at FLOPS/WATT but it does use more power.

It does seem odd, but large voltage increases when overclocking, coupled with lower-quality power circuitry can cause parts to draw more power than those which ordinarily should draw more. A good example is the Anniversary Pentium which, when heavily overclocked, draws more power than an i5 and yet fails to perform nearly as well due to it only having 2 threads and such.

That is NOT going to be SPCR quiet even if they are running at only 500rpm. Amazing to see that this guy has 18 fans right beside his bed!

He said they are limited to 500 RPM but generally run around 350. Those radiators can support 4x 180mm fans also. I was wondering if that would be better for noise than so many 120mm fans. There is also the issue of just running one of those radiators instead of two. If I were to cut down my build to a single 980 and an i7 4970K, for instance, it seems like it would be very possible to use just one of those radiators with perhaps 4 180mm fans at minimal RPM.

It does also lead me to question the guys priorities as he has spent all of that money on his computer yet doesn't have a proper space to put it in so it's in his bedroom. Maybe if he had not spent so much money on his computer he could have moved to a bigger house. Or possibly out of his parents house?!?

It depends upon where someone lives. In some places, a tiny condo is worth millions. If the computer is asleep it can work fine in a bedroom. I have a computer in mine so I can have peace and quiet when people are using the downstairs rooms. I use my Macbook Pro downstairs.

There are watercooling aficionados who brag about running multiple Delta fans with their radiators so I think this Noctua guy has a lot more sense than some. However, I am skeptical about the overall decibel levels. One person's "silent" is another's "loud".

Buy for now. Don't futureproof. Futureproofing never works out the way you plan and in hindsight you always end up looking back and realising that you've wasted a load of money. It's one of the accepted things on SPCR forums.

I don't think it's that simple. If, for instance, you want to support AMD financially it makes more sense, in my view, to wait until 2016 for its Zen platform than it does to invest in the already outdated Vishera platform. There are other examples where it makes sense to look to the future, such as the decision about whether or not to buy a lot of fast DDR4 RAM. When DDR4 hit the market it was outrageously expensive, so it made sense to consider the future while looking to the way DDR3 and DDR2 prices and performance evolved over time. Even now, the latency remains high, which hampers performance.

If Skylake indeed will work with the Haswell-E motherboards then it seems to be worth considering spending a bit more on a motherboard now to be able to have quad DDR4 to feed those chips — and also to avoid having to buy a new motherboard to run the chip. Before using this compatibility factor to inform one's decision, though, it does make good sense to be sure the rumor is true. I need to look into it more. There is also the matter of trusting Intel, which may not be wise, since things have the tendency to change when they actually hit the market. Broadwell is supposed to be compatible with 1150, so investing in that platform could also provide some future-proofing.

Thanks for the comments.

[MikeC]

If you haven't already, you should thoroughly read our Quiet ATX Gaming build guide articles. It may help you think/plan your system better.

http://www.silentpcreview.com/SPCR_2014 ... uild_Guide
http://www.silentpcreview.com/Quiet_ATX ... R5_Version

Both are under 15 dBA at idle/low load; 14, iirc. None of the fans start ramping up at all until the GPU hits >60, which doesn't happen except when gaming. Note that with a single Strix 980 card, the second system manages to keep SPL down to just 17 dBA@1m. The first is about 2 dBA louder.

18 fans.... they could be very quiet, it depends on many factors, but generously let's say they're... say 8 dBA each: 2 of them = 11 dBA; 4=14 dBA; 8=17 dBA; 16 = 20 dBA. 2 more fans would hardly make any difference. This is assuming none of the fans tick or make any of the odd sounds fans sometimes make when run super slow. A couple of them making slight super quiet ticking at slow speed is no big deal; 18 of them... that could be another story.

Then you have the pump -- which is never just broadband, in our experience, there's always a tonal element. They have a much more audible sound quality, and that would add to the fans.

The fellow you cite may be honest & accurate when he says it's super quiet... but no one w/ accurate low noise audio test gear (and the understanding to use it well) or whose auditory opinion I respect has done anything like this, so to me, his path hardly a safe one to follow.

We're going to be posting a dual-970/SLI system guide in the next 2-3 weeks; you might want to wait for that... tho it will be with an 1150 CPU. We build for today; there's no advantage to the 2011-v3 platform for current gaming. (Though this doesn't rule out us trying to do a silent gaming build on that platform some time in the future... just not today.)

[xan_user]

I know OP wont see this, but heres a cool way to use water cooling silently.

http://www.overclockers.com/pc-water-co ... -radiator/

https://www.youtube.com/watch?v=b8bLtg9 ... -yeJA0Tunw

[MikeC]

I know OP wont see this, but heres a cool way to use water cooling silently.
http://www.overclockers.com/pc-water-co ... -radiator/

I remember this! iirc, the guy's in North Van, I might even have met him.

https://www.youtube.com/watch?v=b8bLtg9 ... -yeJA0Tunw

Another Vancouver fella -- Linus loves to play goofy. This has been done before; someone buried a whole tank in the backyard while building his house -- to be a reservoir for computer cooling.

[edh]

unless there is an issue with electrical noise.

Now that you bring up electrical noise... you do know that with those two PSUs you're going to have a separate ripple voltage on each along with all of the other kinds of power distortions. You're ruining your power quality by having 2 PSUs and a dirty common GND between them (earth looped of course) even if things do work correctly (that gadget you linked to only gets over startup issues, nothing else). Worse power quality means worse overclocking potential.

Two fanless power supplies can't make more noise than a single power supply with a fan

That's not the point. A single decent fan cooled PSU can't possibly be as loud as all of the other components you're going to have. Why bother having something quieter when it will be drowned out anyway?

As I said, I have yet to see evidence of an actually silent single power supply that can provide high wattage. They all spin up. Reviewers invariably try to rationalize this with the comment that "some other part of the system will be louder anyway", as if that eliminates the additional noise contributed by the power supply.

You're disagreeing with a lot of very experienced reviewers (and just about everyone on these forums) by saying that.

Therefore, the only solution I am left with is to use two passive power supplies. If you have a better idea then post it.

Buy a single fan cooled PSU. That's what everyone has been trying to convince you of all along. If you don't like that answer, don't carry on asking the same question.

like the idea of not having to buy a motherboard again when Skylake hits

Don' count on it. New CPUs aren't always compatible with old motherboards. Sometimes a BIOS update will fix it but there is a history of some motherboards not being supported. It could be a year until Skylake so I wouldn't blame them for not supporting a major new CPU after that time. You also won't get USB C or any of the other changes that the next gen chipsets will bring with Skylake.

like the idea of having quad channel DDR4 at high speeds available on the motherboard for feeding Skylake when it does hit.

Not money well spent right now. DDR4 is hugely expensive and compared to the speeds you'll be able to get in a years time, the current DDR4 will be outdated and slow. This always happens when a new RAM architecture is released: the initial speeds fall by the wayside pretty quickly. Remember PC1600? Or PC2-3200?

Do you think it's possible (safe, especially) to use two fanless PSUs, perhaps with something like that unit I linked to?

I believe we have all mentioned it a few times but in case you've missed it, no.

Part of the reason for building around a bit more wattage than peak maximum was also to provide a bit of headroom for future equipment upgrades.

Build for now. Don't try and futureproof.

There is also the non-issue of capacitor aging with PSUs.

Fixed.

I don't think a quad is superfluous. Gaming engines are beginning to require 4 threads to run smoothly at high settings. There are already some that run better on an i5 than on an i3.

You may misunderstand me. 4 cores might be faster than 2 cores but is 4 cores faster than 3 cores? Basically there is still unused silicon quite a lot of the time when gaming. Heed the advice of everyone here and use an i5.

I don't want to invest money into this setup and have to reduce quality settings to avoid annoying stutter.

Do you want to 'invest' in it and find it's really noisy? No. You need to compromise. Faster cards will come along in future.

If the computer is asleep it can work fine in a bedroom.

If, and it is a really MASSIVE if, that guy with the 18 fans on his wall brings a girl back, he's going to have a lot of explaining to do when she asks why his wall is covered in fans. Nothing is as powerful a contraceptive as this.

There are other examples where it makes sense to look to the future.

Then wait and buy a Skylake. Buying a massively expensive Socket 2011 motherboard this year is not going to give you any of the advantages of Skylake. Time and time again people come up with really weak justifications for spending more money based upon some future intention that then never materialises. You're wasting your money in doing so. Either build yourself something along the lines of the Quiet ATX gamer build on SPCR or wait another year for Skylake. Whatever you chose: Use ONE PSU.

[RIchardF]

unless there is an issue with electrical noise.

Now that you bring up electrical noise... you do know that with those two PSUs you're going to have a separate ripple voltage on each along with all of the other kinds of power distortions. You're ruining your power quality by having 2 PSUs and a dirty common GND between them (earth looped of course) even if things do work correctly (that gadget you linked to only gets over startup issues, nothing else). Worse power quality means worse overclocking potential.

There is no need to be emotional about this. I asked about this because I didn't have the answer and wanted to learn what the answer is. Your posts have the tone that all of this is something someone should just automatically know. I did a Google search and found nothing that directly addressed the issue of chaining two fanless power supplies together. Plus, I was hoping to not have to link them and instead power just some components with one and some components with the other — precisely to avoid any issues caused by linking two together.

That's not the point. A single decent fan cooled PSU can't possibly be as loud as all of the other components you're going to have. Why bother having something quieter when it will be drowned out anyway?

I answered that question, but I guess you missed it. Decibels don't just disappear because some other component produces more of them.

You're disagreeing with a lot of very experienced reviewers (and just about everyone on these forums) by saying that.

That's the bandwagon fallacy. All that it takes to disprove my assertion is a bit of concrete proof. One chart could do it. I do not doubt that there are people with more experience than I have. I also do not doubt that people are fallible and engage in rationalization.

Buy a single fan cooled PSU. That's what everyone has been trying to convince you of all along. If you don't like that answer, don't carry on asking the same question.

Dogmatic responses are not what I'm looking for. If you want to be certain about something then just post a chart that concretely demonstrates that you're correct. The potential for two separate passive power supplies to be quieter than one with a fan is something that is objectively true. Passive units do not have fans so they cannot have fan noise. It is possible to make power supplies that do not have significant audible electrical noise.

However, we also have to deal with the limitations of existing products, such as the way GPUs use power both from the PCIe slot and from PCIe connectors, which, I assume, makes it difficult to power them with a different PSU than the one used to power the motherboard (which includes the CPU).

DDR4 is hugely expensive and compared to the speeds you'll be able to get in a years time, the current DDR4 will be outdated and slow.

One strategy is to buy inexpensive slow DDR4 now and then upgrade to faster DDR4 later. The slow DDR4 can be used with a budget system that one gives as a gift to a relative. If Skylake is indeed compatible with the Haswell-E motherboards then not having to buy a motherboard later could represent a significant savings.

I believe we have all mentioned it a few times but in case you've missed it, no.

It was mentioned briefly, without addressing that unit I linked to which has good reviews on Amazon.

Basically there is still unused silicon quite a lot of the time when gaming. Heed the advice of everyone here and use an i5.

You're thinking too narrowly. This post isn't merely about what rig can be put together with air cooling that will be quiet. It's also about whether or not the large radiator solution can be a solution for people who need higher wattage rigs. Whether or not 6 or 8 core Intel chips are needed for gaming isn't particularly relevant to that question. There are workloads that benefit from having the additional cores.

I can personally get by with a quad but someone who needs more power could benefit from substantive answers to my questions. The world of computing doesn't revolve around gaming and people who need a 750 watt peak system, for instance, or one that draws even more should not have to be forced to hear significant PSU noise in my opinion — or significant noise from other equipment such as GPUs.

If, and it is a really MASSIVE if, that guy with the 18 fans on his wall brings a girl back, he's going to have a lot of explaining to do when she asks why his wall is covered in fans. Nothing is as powerful a contraceptive as this.

I have been married for 17 years. I have no need to impress anyone with my setup. I did mention that earlier, too. However, it is certainly obvious and true that most people will find a jury-rigged external setup to be less aesthetically appealing than one that's confined to a computer case. But, it's also possible, as I said, to build an enclosure. My mother is quite good at working with wood and metals and has the equipment. I could hire her to make a custom enclosure. This would be ideal because it would help with dust filtration and also keep my cat out of the picture.

Buying a massively expensive Socket 2011 motherboard this year is not going to give you any of the advantages of Skylake. Time and time again people come up with really weak justifications for spending more money based upon some future intention that then never materialises.

Gaming, unless you're in the industry and being paid to do it, is a waste of time and money, according to some viewpoints. Even worse... some believe FPS gaming in particular increases aggression and anti-social attitudes (even if it doesn't actually increase levels of violence). According to others it is a safe and comparatively inexpensive way to relieve stress, socialize, and so on. Some argue that buying a Vishera platform is worthwhile. The CPU and motherboard combo from Microcenter for an 8320 is $150. Advocates argue that, despite the much lower performance per watt and the 2 year old platform, it's still a better value for most gaming workloads. There are a lot of differences of opinion when it comes to value.

Contemporary 3D computer gaming is a luxury item and carries a luxury premium. (A budget alternative is going outside and hitting a plastic badminton bird or throwing a football — or playing ping pong indoors.) You can get a passively cooled computer that uses very few watts and which takes up very little space for very little money that can do practically everything, even rendering (albeit very slowly), except provide enough frames per second for standard 3D games. The more luxurious your experience, the more you will pay. That goes for noise as well. It's less expensive to buy a loud system at the same performance point. But, for me, noise is a critical factor in performance. Part of the point of this topic is to explore the question of whether or not it's actually possible to produce a watercooling setup (within reason) that enables the use of more luxurious equipment, such as 6 or 8 core Intel chips — or an AMD Vishera heavily overclocked which is very budget except in terms of cooling and performance per watt. Another part is to look at strategies for power supplies that don't involve being limited to the ATX form factor, a form factor that wasn't developed to handle such high wattage and which seems to require significant noise to deal with it — if one only uses a single PSU. (Manufacturers are realizing this, as power supplies are creeping in terms of length. However, no one has yet committed to making, for instance, a double width PSU and a case to match.)

If you're uninterested in those latter questions that's fine. But, there is more to this topic than my particular build and choices.

[edh]

I'm not going to respond on any more of your long reply as we'd simply be going over the same material again.

What about this? http://www.add2psu.com/

It has good reviews on Amazon.

I did reference this before but I'll come back to it in particular as you've missed (or ignored) my reference too it. It won't fix most of the problems. All it does is make sure they switch on at the same time, that's all. All of the other issues remain.

It's total, total fallacy to run dual PSUs. Everyone on here is telling you that. If you don't like that answer, don't carry on posting asking if it'll work.

[RIchardF]

I'm not going to respond on any more of your long reply as we'd simply be going over the same material again.

It's total, total fallacy to run dual PSUs. Everyone on here is telling you that. If you don't like that answer, move on.

My reply was written for people who are interested in the topics being discussed, even though I quoted your post. If everything I have been addressing had indeed been completely answered then I wouldn't have continued to post. You also don't get to tell me to move on in my own topic. If it's too much effort for you to read what I wrote carefully and thoughtfully and respond in that manner then it would be more helpful for you to take your own advice.

[MikeC]

Decibels don't just disappear because some other component produces more of them.

Actually... they kind of do.

Let's say your PSU w/ a single fan measures 12 dBA@1m. And your 18 fans -- -- measure 20 dBA@1m. The total SPL from the setup (assuming it's all more or less in one area/case) will be perhaps 20.2 dBA. In reality, with the fans on, you will not be able to hear whether the PSU is on or off (without sticking your ear right up to it). In fact, this is true until there's less than ~6 dBA difference between the two noise makers.

Of course, if one of those noise sources is broadband (smooth woosh) and the other is tonal (eeeeeee or ooooooo or bzzzzzzzzz), the tonal noise will certainly be additive.

btw, since it sounds like you're going to go down the path less traveled, I suggest you don't encase any noise makers -- like 18 fans. Leave them as unenclosed as possible to avoid the air resonance effects you'll get when you enclose (or even partially enclose) any noise maker.