Building an inaudible Quad-core PC in a custom-case

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OddSilence
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Location: Portugal, EU

Building an inaudible Quad-core PC in a custom-case

Post by OddSilence » Wed Jul 28, 2010 1:56 am

Edit:It's all pretty much cleared/decided now about my system, but there are some interesting posts/links down this thread, about using several fans, noise, etc, you might want to check those out.

(I'm sorry for such long post.. I'll try my best to organize it.)

Hello,
I have finally decided to try my idea (discussed here) of building a semi-high-end computer in a custom-case with 6 high quality ultra-low RPM fans (120mmm @ ~375 RPM).

(I ended up buying several "NoiseBlocker PL-1" fans because: they were 12€ instead of the 18€ that the "NoiseBlocker M12"s cost; and they use the same technology, but with a normal frame.)

Objectives:
- powerful computer
- inaudible(down to 30 cm)
- without high temperatures
- without dust
- want it to last for "7 to 10" years :)

Uses:
- Audio/music recording
- Casual gaming (not very new games)
- Watching TV / Video
- listening to music, using the internet, etc


Components
Components that i have bought already:
- Processor: Intel Q9550
- Mainboard: X38 high end
- RAM: 4 modules of DDR2 800 (with ECC)
- storage: Intel X25-M SSD
- GraphicsCard: ATI 4670
- CPU cooler: Scythe Orochi (@passive)
- Fans:
  • - 1 x NoiseBlocker M12-S1 (@5v: 312 RPM)
    - 5 x NoiseBlocker PL-1 (@5v: 375 RPM)
Undecided components:
- GraphicsCard Cooler;
- Power Supply;
In the future I only expect to add a TV-tuner card and a second SSD (when prices fall..).

Context:
- I'm thinking of building a big desktop case with 50cm x 50cm
- Either [50x50x~25cm] or a cube[50x50x50cm]. (that would be a monster case! :shock: )
- (motherboard in horizontal position)
- Very big Filter with big distance to the Fans to not restrict the airflow.
- [edit:] The idea is to distribute the cold airflow through all components (giving special attention to the hottest ones), and to avoid having the airflow to any hot component having passed through other hot component. So there is a path for PSU, a path for the GFCard, and a path for the CPU.
- [edit] The only "mechanical" components are the fans, there will be no internal hdds nor optical drives.
- [edit:] The intake fans (i.e. 4 of the total fans) are "internal": they will be >10cm within the Case, with a big filter between them and the nearest open side.
- Scheme of the idea: Image
(Note: The SSD is not there, because I can decide later where to put it, since it is very small and has no cooling requirements.)


Help request
I would appreciate any comment on my idea as a whole, and particularly I ask you to please help me decide these last two components:

By your experience and knowledge,

GraphicsCard Cooler
I'm thinking of either a AC-Accelero-S1 or a AC-Accelero-L2-Pro without it's fan.
As it is a horizontal mount, the fins of the S1 wouldn't stand in a good direction for low-airflow cooling... :(
I think the L2pro could be mounted with the fins vertical (can it?), but would the L2pro be able to handle the 4670 without the fan?
Do you know other affordable options for my 4670? (i think once i saw a vga cooler from Scythe...) [I don't want to spend much on this, or I might as well just buy another card that has already passive cooling...]

PowerSupply
Of how many watts do you think the PSU would need to be?

I want a PSU with 12cm fan @ Zero to 400 RPM.

I think I have two options:

PCP&C Silencer 750

- I already have a Silencer750 (I know it is too powerful, but was the high-quality psu i could find at the time) which for some time I thought about modding by replacing the 80mm fan with a 120mm (mounted externally), but in the specifications is stated that the original fan does between 22CFM and 55CFM. I think that would mean a minimum ~600RPM 12cm fan, which doesn't suit what I want... :(
- Since the PSU will be in a separate chamber and I won't be using more than half of the PSU's capacity for sure, I wonder if it would be sufficient a fan that could spin at [375 to 900]RPM.
- I have thought of trying it, but I'm afraid I would damage the PSU because I don't know what would happen when giving the PSU a considerably smaller airflow than the minimum it expects...
Do you think the PSU would instantly increase the speed if it needed, without getting damaged nor decreasing it's life?

Seasonic X-650
(I think a 400w would be more than enough, but here I can only find the 650w and 750w models.)
I consider buying a Seasonic X-650 if really needed... (ouch! @ price)
I guess this would be perfect(if i don't count the price), since the PSU would be separate from the rest of the components the fan would probabbly usually not even spin... 8)
Do you think the airflow of the case would be too little for the PSU?

Other options (if you think I can't use the Silencer750):
- "Enermax Pro87+ 500w" but that doesn't have all capacitors japanese, I fear it might have worse quality, is only ~30 euros less than the Seasonic and it's fan would spin at 330RPM, but it is a 14cm fan, so it would correspond to a higher RPM 12cm fan (wonder how high?)
- "Enermax Pro82+" but it isn't possible to change the problematic fan, and even if I could, probabbly it would have to spin too fast.
- Do you see other option? (I want a high quality PSU with all japanese capacitors, at least bronze efficiency and either fanless or less than 450RPM, with a silent fan, or a fan that can be swapped)


So what do you think?

Thankyou for reading and for any comments/help.
Last edited by OddSilence on Tue Aug 03, 2010 6:59 pm, edited 5 times in total.

tim851
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Post by tim851 » Wed Jul 28, 2010 12:41 pm

Why wouldn't it work? Your components are not really what I would even call semi-high end anymore, the CPU is pretty on the lower spectrum of the "performance"-segment, being outperformed by the baby i5-750 and your GPU was a mainstream product 2 years ago.
There are countless examples on these forums, where people cool much more high powered computers silently without the trouble of a custom case.

In your place, I'd seriously reconsider the "last for 7-10 years" approach. Even with things having slowed down recently, just think back 7 years: Considering your PC is already less than up-to-date, we're looking at the equivalent of a Pentium 4 Northwood with 2.4 Ghz and a Radeon 9600 card in '03. Now I know people who still use something like this, but it ain't pretty!

10 years ago we're talking about an original Athlon @600 Mhz with a Riva TNT2 card. Some of these are now used as Routers...

OddSilence
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Post by OddSilence » Wed Jul 28, 2010 1:10 pm

@tim851: Thank you for your reply. When i wrote 7/10 years, i meant i wanted it to last for long, not fry it with high temperatures, etc. Of course probabbly it won't be my main computer at that time, but probabbly it will still be usable (since it has 8GB of ram and Windows7-64bits).
(My laptop is a celeron 800Mhz, and is still minimally usable for text or internet stuff, although starting to strech it... ^^).
Sorry if i didn't explain myself well.
When i bought the components they were more up to date... Unfortunately had to delay this subject for personal reasons.


Also, I want to record voice/music with a fairly-quality recording interface (Presonus FireStudio Project) and a minimally decent microphone, near the computer, so I want it to be as quiet as possible, without sacrificing performance.

Thanks,

alleycat
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Post by alleycat » Thu Jul 29, 2010 4:37 pm

I don't think you need to build a custom case. Just buy a decent case now, and you can start enjoying your new computer immediately, rather than messing around with building something unproven and/or procrastinating even longer. A purchased case will be smaller and lighter than anything you will be able to build yourself. You should be able to build a PC which is basically inaudible with a good quality case and two exhaust fans. Intake fans are unnecessary in my opinion.

Personally, I wouldn't worry about the dust issue either. It's much easier to vacuum the inside of the case every few years (if at all) rather than worry about cleaning filters every couple of months. Filters will definitely get clogged, whereas dust on the inside of the case may have minimal effect on heat and noise.

Also, there's no need to get obsessive about temperatures. It's not going to make the tiniest difference whether your PC idles at 30, 40 or 50C. I've got an inaudible P4 system that I built 6 years ago which runs quite hot, but has been 100% reliable, and that was before the newer high durability capacitors became available.

OddSilence
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Post by OddSilence » Thu Jul 29, 2010 6:09 pm

Ok, really many thanks alleycat.

Case: I agree it's probabbly not good idea to make a custom case and would take even more time (was getting there myself and you helped too!). So I'll have another look around for cases and this time have a less tight criteria in several aspects (example: this time consider steel cases - maybe a AntecP18*, something with PSU chamber and ways of sticking several fans and filters [might cut down 1 or 2 :) ] ).
And I'll have to mantain it lying down in a horizontal position.. because of the mammoth CPU cooler! :oops:

PSU: I have decided to not buy the Seasonic X-650 (would be a dream, but it's too expensive! - 179€ here :shock: ). I think I will either:
- use the Silencer750 with a 120mm 583RPM fan or
- buy a EnermaxPro82+425w [and change fan - i know it uses a non-standard connection, maybe i'll use the 12v wire and connect 2 equal NB-PL1 (900RPM) fans in series(use one as case intake) -> 450RPM@6v each)].
I guess my system wouldn't use more than half of the Enermax's capacity, and I saw in their website that @25ºC ambient the fan spins @450RPM until 50% of the capacity, what a coincidence :O .
I guess I can mount the PC with another PSU and see how much it consumes to confirm.

GraphicsCard: i'll cool it temporarily how i can (might buy a L2pro though), not worrying much about it's health :twisted: , and buy a DX11 card with "native" passive cooling some time from now...

Filters: Sorry, but on this I can't change my mind... :P

A thought: I don't regret having bought this system even though I had to wait to assemble it, because(at least as far as I know) the X38 chipset was the last non-server Intel chipset that supported ECC RAM, which I really wanted; Also, speed isn't everything.

So, you can consider my case solved for now I guess.
Thanks alleycat and tim851, and sorry for trouble.

netmask254
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Post by netmask254 » Thu Jul 29, 2010 8:10 pm

I suggest you wait for a couple of months, for Thermalright HR02 and X-fanless 400W, which should be better choices for your configuration.

BTW, I really don't think you need so many fans, perhaps 1~2 is enough.

OddSilence
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Location: Portugal, EU

Post by OddSilence » Sat Jul 31, 2010 9:19 am

@netmask254: Thank you for your reply,
I might assemble the system temporarily on a case i have here without worries about the noise, so i can start using it, while I decide/implement the last details, and also to be more certain about the power consumption/requirements.
About the Seasonic X-400, I don't have much hope to be able to buy it, since only 1 store in Portugal has the Seasonic X-650 and X-750 (as far as I know, though i've looked in many(if not all) online stores, including many targetted at enthusiasts). But as I'll leave the PSupply for last, who knows the X-400 might show up. :)

About the number of fans, I might reduce a bit, but I wanted several to be able to run them at ultra low speeds.

Thanks once more,

bonestonne
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Post by bonestonne » Sat Jul 31, 2010 10:39 am

If you're still building a custom case, I would focus on the growing availability of larger fans, rather than more fans.

1 or 2 fans that are 140mm or larger will give you just as much cooling ability, while keeping the noise lower. I don't remember where it is, but 2 fans running at the same speed will be 3dB louder than a single fan. You're looking at a lot of noise being added just by having 6 fans (6!).

If you've got a Scythe Orochi in mind, and an Accelero S1, you don't need 6 fans. You need 3 at the absolute most.

http://www.kwikpiks.com/files/129/IMG_0997.JPG

Thats my rig, with 3 fans + the PSU fan. Specs are in my sig. Placement is far more important than the number of fans.

As for the PSU, Europe is pretty small, so I would say try looking into other stores that could ship to Portugal, Spain is right next to you, Germany isn't that far away. Online shops generally ship all across EU there (unless otherwise noted).

I have a Corsair 400CW, which is great, and my system is about the same as what you're planning. There is also the Nightjar PSU, but I'm not sure about availability.

Filters wont always help you, but they do make a difference at times. I wouldn't worry about using filters, I would worry about keeping the computer clean every 2-3 months. Filters help you, but you still need to keep the computer clean every 6-7 months (I have a Cooler Master Elite 330, and the filters do stop most dust, but dust will still get in).

OddSilence
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Post by OddSilence » Sat Jul 31, 2010 8:37 pm

@bonestonne: Thanks alot for your input (suggestions and useful information),

[I'm sorry but I distracted myself and I think I typed too much... :oops: So, feel free to not read all of this, and just jump to the conclusion]
If you're still building a custom case
Haven't decided yet, thought about the Antec P18*, but when looking at it better online, [Edit: thought at first it had a restrictive grill on the back exhaust but I must have been sleepy at the time... after all it doesn't seem so restrictive (the front seems more actually, but i'm probably sleepy again..)] I've seen a 50€ steel case with a back-fan grill cut like a Lian-Li's (= clear hole), so for a fairly expensive case, how/why does Antec make it like they did!? :?

I would focus on the growing availability of larger fans
I have already bought the fans and can't return them, but no worries, i'm pretty sure these are good enough. But yes, maybe I should have bought 140mm for outtake... Although this way I can still opt for a standard case.
I think NoiseBlocker's most known fans around here(spcr) are the "BlackSilentFan XL1 and XL2", but those are their "lowest tech" fans; the ones I bought are their "high tech" ones :)
1 or 2 fans that are 140mm or larger will give you just as much cooling ability(...)but 2 fans running at the same speed will be 3dB louder than a single fan(...)
If, by any chance you feel like discussing the subject, here are my thoughts:

- Yes I agree, given 2 fans of different sizes (but using the same technology), the bigger fan should move more air. (at least in an unrestricted situation, because otherwise it would suffer with the pressure lost, right?)
- I might be wrong, but I also think that 2 fans at half of the RPM of another fan, should make less noise than that other fan while moving the same amount of air (with the same caution as the above situation about the pressure loss) [If for no other reason, than because of the airflow being distributed through more space and hitting the fans' surface with less intensity, etc].

- I think I need to clarify my idea:
This last reasoning was the reason I was thinking of using more fans.
With it I also meant to avoid passing the hot air through several components: 1 fan would get the CPU's hot air out, the other fan would get the Chipset and VGA card's hot air out.
So VGA's hot air wouldn't go through the CPU and the components hot air wouldn't go through the PSU.

In reality my idea uses only one more outake fan than yours(which looks nice btw :) ). The intake fans are because of the "filtering system" for achieving slight positive pressure... (or else the filters wouldn't be effective)
[since intake fans are in series with the outtakes, they don't add airflow, only pressure]
Just want to point out that if I built the case, the intakes would be so deep inside the case that they would be internal fans and consequently be less meaningful in the noise equation than it may seem at first glance (at least I think so).
(...)You need 3 at the absolute most.
Please suggest/inform me, roughly, the RPMs at which they would need to spin; but you mean a configuration like you have, right? (with no intakes if i understood well, if so, unfortunatly that wouldn't suit my filtering "need")
(...)PSU(...)Nightjar PSU
The nightjar is available but it's very expensive: 149€ (for 300w) and 166€ (for 400w), so the money would be much better spent on a Seasonic X-650 !!! :o
Anyway, although I would love to own&use a SeasonicX650 unfortunately I have determined I can't afford buying an expensive PSU at the moment. But I think there is no real need to either: I can buy a "Enermax Pro82+ 385w" for 64€ (or a 425w for 71€), which have all the minimum features I would need/like, like all capacitors being japanese. Only problem is I would have to change the non-standard fan.
(but maybe the SeasonicX400 "pops-up" in the meantime..)
Filters
Well, I agree, and I don't expect it to work 100%, but i think that partially it depends on the type of filters being used too, some let more dust pass through than others (though all let some go through of course)... I was thinking of trying to use a vacuum HEPA filter... :oops: If that worked well (not restricting the airflow too much, etc), that would really stop almost all of the dust.. :D

_________________

@all
Concluding: I thank everyone for their replies, they were useful. Now I need to clear my mind about this*, as I said previously, as soon as I can I'll assemble the system temporarily on a case I have here to check for sure how much it consumes and to be able to use it while I "decide&'implement'" the PSU(probably the EnermaxPro82+425w) and Case (which I still haven't decided if standard or custom, as i said i need to think). But something came up and probably can only dive into this a few days from now.
I'll post here how it goes for anyone who may care / be curious, if any. :P
(*but feel free to post more information/suggestions)
Last edited by OddSilence on Tue Aug 03, 2010 7:04 pm, edited 2 times in total.

bonestonne
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Post by bonestonne » Sun Aug 01, 2010 9:29 am

http://www.kwikpiks.com/files/172/My%20 ... G_8791.JPG
http://www.kwikpiks.com/files/172/My%20 ... G_8790.JPG
http://www.kwikpiks.com/files/172/My%20 ... G_8788.JPG
http://www.kwikpiks.com/files/172/My%20 ... G_8787.JPG
http://www.kwikpiks.com/files/172/My%20 ... G_8789.JPG


Those are the important pictures, I know they aren't all focused perfectly, but they should get the idea down. My case is the Cooler Master Elite 330, which does have filters on the front, so I should hope it's relevant enough for this.

The point I'm trying to get across is that you don't need intake fans just because you're running a filtered computer. Another point to take into consideration is that my computer does not run with C1E or Intel Speedstep, which basically means, my Q9400 is running at 2.66ghz all the time. I also have HPET disabled, and no power management set up, because of my sound cards. My computer does not get hot until it's really under a lot of stress, so when you break it all down, your computer should run cooler, and use less power than mine even with the same basics (quad core, mid-high end graphics, lots of RAM, large display).

The only game I currently play is an old one, American McGee's Alice, and it's absolutely rock solid on my setup. I haven't tried it with the 22" monitor yet, but I don't see why it would be any different.

My fans are also all mixed. I have a Delta 92mm fan which runs at 7v, I have an NMB 120mm fan running on my Scythe Ninja at 7v, and I have a Cooler Master 120mm fan running for exhaust off the CPU header so that it is automatically adjusted, however I still need to replace it with a PWM fan, because it is an older 3 wire fan, and not fully adjustable on the PWM circuit.

The fans run very well, the exhaust fan did rattle for a while (causing a lot of vibration) but after soft-mounting it with rubber fan mounts, it is near silent. As long as there is a lot of space for air to move around without obstruction (cables kept neatly tucked away, routed along the edges, and only where they need to be) your computer shouldn't have a problem no matter what case it's in. I've been trying to upgrade my case to an Antec Fusion Remote Max, but if I can't, that's no big deal, it's still very quiet, with the power on tap whenever I need it.

As for the design of many computer cases, most companies keep in mind that there could be animals or children that could potentially stick their fingers in a computer fan vent, so having tight grills makes it a safety feature, at the same time, it's a lot cheaper to drill a few holes in a grid rather than cut out a whole circle. Manufacturing costs are kept down like that.

Yes, if you have a bunch of fans running at lower RPMs, it is quieter than less fans running at higher RPMs (but it could also be the same noise, it depends on the fan). I haven't cleaned the filters on my computer in some time (laziness and I also haven't really used it as much lately, because my laptop makes it easier for me to do basic internet browsing at lower power usage). When it comes down to the heat production, that's why I have so many massive heatsinks in my computer, because I'd rather have the heat dissipated quickly rather than just have another fan in there to take care of it.

The Scythe Ninja (original model) on the CPU keeps temps down very low.
The Thermalright HR-05 on the Northbridge keeps temps down nearly 15-20C lower than the stock heatsink.
The Accelero S1 Rev 2 keeps temps ~20C cooler than the single slot cooler the ATI 4850 shipped with.

Hard drives are placed in front of the lower intake area, and even in their current positioning, do not exceed 40C (even the Raptor stays around 37-38C).

The gaping hole below the optical drive is what keeps things cool. The PSU and the CPU get air from this area, and you can stick your hand directly in front of the filters and feel cool air being sucked in. You can do the same at the bottom of the case.

The importance of this is that there is a rabbit and a guinea pig at my house, and the guinea pig is in the room with all the computers, and the rabbit also sometimes is let out in this room (because this is where people are mostly). That makes for a ton of dust and fur to get everywhere, however as you can tell from the pictures I took just today (at the beginning of this post) there isn't much of any dust in there. I haven't cleaned the filters since maybe May, if not longer than that.

I don't really measure the RPMs of my fans, because that's just anal, but to be honest, I would say the CPU fan is around 800RPM, the GPU fan is around 900RPM, and the exhaust fan is between 1000-1200RPM.

As for the Power Supply, yes, the Nightjar is expensive, I tossed that out as an idea, as it's fanless. I would say the Enermax Pro82 425W would be plenty, it's around what I have in terms of wattage, and does me just fine with daily usage, gaming and working.

I think you should be set with that information, but absolutely ask more questions if you want, that's what we're here for.

joetekubi
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Post by joetekubi » Mon Aug 02, 2010 5:52 am

bonestonne wrote:If you're still building a custom case, I would focus on the growing availability of larger fans, rather than more fans.

1 or 2 fans that are 140mm or larger will give you just as much cooling ability, while keeping the noise lower. I don't remember where it is, but 2 fans running at the same speed will be 3dB louder than a single fan. You're looking at a lot of noise being added just by having 6 fans (6!).
Uncorrelated (ie: white noise) audio sources produce +3 dB for each additional source. Correlated audio (say 2 midranges or woofers in phase) produce +6 for each additional source.

You probably know all this already, but for those who need a refresher (like me):
http://www.santafevisions.com/csf/html/ ... relatedadd

bonestonne
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Post by bonestonne » Mon Aug 02, 2010 6:54 am

viewtopic.php?t=19297

It will vary from fan to fan, and is not a 100% set in stone rule, but for "average" fans, it will be about right.

A good read for people trying to find noise about fans specifically (for those who haven't already read through it).

OddSilence
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Post by OddSilence » Tue Aug 03, 2010 9:24 am

@bonestonne: thankyou for your long and informative reply,

Your photos are nice, and I wish(and would consider myself lucky) i'll be able to have a case as tiddy as yours! :)

About the filters, I noticed you blocked the side vents of your case, which reduces the air that doesn't go through the filters, but some air would still get in through smaller openings like: "front USB ports", motherboard's ports, PCI card slots, etc
But I don't mean to diminuish what you've done, it's very good! And probably enough to stop the dust. (and i'm probably crazy for wanting to stop even more... oh well...)
And negative pressure (like in your case) is probably more efficient in terms of cooling.
I conclude is a personal trade-off and a matter of balancing and pending to what a person values the most.

About the grills, I think the grills that have more and smaller holes, but have very thin and "rounded" wires, so not with flat surface, should be less restrictive and make less noise, but as you say, they cut down on costs...

- By your RPMs I think I was aiming at a more near-silent system, at what distance do you have to be to be able to hear yours?

- Having mounted and used an Accelero in a vertically-mounted-system, do you think it would perform well in a horizontally-mounted-system? (not asking you to try, would be too much trouble, just to tell me what is your feeling about it, please)

The information you provided about your system is interesting and will be helpful to help me think.

Thanks, bonestonne, for all your effort.

OddSilence
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Post by OddSilence » Tue Aug 03, 2010 9:35 am

@joetekubi: :!: Very interesting document, many thanks! But I'm not taking the same conclusions from it :?, since there it says:
How correlated waves add is enormously affected by the phase angle.
And in more detail at other point of the document:
Phase alignment•When correlated sounds are added the reult depends on their phase alignment. •Sounds which are aligned will add •Sounds which are not aligned will cancel each other out at 180° •At other angles they will combine destructively to some degree.
So, only if two correlated sounds are aligned, we get an added sound, in any other situation the sounds destruct eachother at least partially.

@bonestonne: nice, some very interesting stuff too, though confusing :?, [i don't remember well, but maybe this was one of the things I read online a few years ago]


Trying to apply the information(from both your sources) to my project:

- I wonder, since most of my fans are of the same model, if it would mean "correlated sounds" at least partially / at times, in some way?
If that is true, I really doubt it happens to have them all phase alligned! So if it was like that, there would be some level of cancellation.
- If not, it would be a 3db increase for 2 fans @ X RPM instead of one @ X RPM; But remember what I would be doing would be 2 fans at half of the "target" RPM, which I think would cause a reduction of much more than the 3db... So for me that would be winning (loosing in pressure though)
- Anyway, the fans' noise doesn't spread in a unidirectional way, so i guess it's too unpredictable and complicated (at least for the dumb me) to predict...

- The arguments in the thread refered to by bonestonne are contradicting and I don't know who is right, if anyone..., So although very interesting, ended up confusing this matter for me even more.

- Anyway I think i can assume that even if it woudn't be quieter, it wouldn't be noisier either...

But whoever/whatever is right, whatever happens when running 2 fans instead of one, etc, I don't see many people remembering this (that I've wrote in this thread already), and that I have no reason to think is not true:
My belief is that putting less air through a confined space (read: a fan) by distributing it through 2 or more equal spaces(read: fans) so the air moves more freely, should make less noise.

So, my convictions at this point are:
(for equal and noiseless-bearing fans:)
- 2 fans in parallel at half of the speed of another fan, should make less noise, but loosing pressure;
- Doubling that in a push-pull configuration should counterbalance the pressure-loss and still make less noise, if not for other reason than at least for
- putting less air through a confined space(a fan) by distributing it through 2 or more equal spaces(fans) so the air moves more freely, should make less noise.


Which was more-or-less my point when I thought about this. So, since:
- I unflexibly want to have a well filtered case;
- Filters loose their efficiency in a negative pressure case unless the case is "air-tighten" (which is basically impossible/impractical to achieve), because air would enter from every opening (incuding USB ports, motherboard ports, etc) without passing through the filter; [I don't need to read or ask anyone about this, because it's simply logical]

I still want a positive-pressure case (but can be just slightly), which forces me to have intake fans.

So my original idea roughly stands as my goal (although now I'm thinking of 3 intake fans instead of 4).

And if no one tries building a computer with many highquality/noiseless ultra low rpm fans, how can we be sure it doesn't work well? :P

bonestonne
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Post by bonestonne » Tue Aug 03, 2010 9:58 am

Actually, I can't say air has a way in other than the front of the case. The PCI slot fillers are all solid now (I know in older pictures I had a vented one near the Accelero).

I'm currently waiting on a case upgrade, I may get the Antec Fusion Remote Max, which will swap all my parts into, however the part that needs real addressing is the heat movement.

In terms of noise, I have a raptor, which is not silent, so it crunches away constantly, and I've accepted this, as the speed is important to me, working with audio, but if I were to unplug the raptor, or boot into linux, which resides on a different drive, the system is calm and quiet until you get under the desk with it. Late late at night when I'm the only one up, and the house is quiet (central air con is off, or between cycles) the computer has a very faint turbulence sound, which is actually because of how I have those 3 120mm fans in the top of the case (PSU, Exhaust and CPU). They all push air at each other, and cause noise, but if I were to stop 1 or 2, the sound is completely gone.

The accelero is much like the original ninja, where it only needs a little bit of air to be happy. I prefer the direct cooling because my 4850 has been re-flowed, and if it gets too hot it will have problems again, but I could easily use a front intake fan to cool it, but I would have to re-arrange my hard drives to allow that. If the cooler were mounted vertically rather than the horizontal like in my case, I would expect the cooler to perform about the same, maybe 1 or 2 C warmer, if it gets any warmer at all.

If you give the case a week or two without cleaning it, those smaller gaps for dust to get in will fill with dust (i know, it sounds bad) but no more dust will enter. USB ports don't actually fill with dust if they're used often, and the small spaces will get patched by dust on their own quickly enough for the inside of the case to stay very clean for several months at a time.

I would advise letting things settle and seeing what the result is like before grabbing the caulking gun and sealing up the case completely except for the fan areas.

About the fan grills however, more and smaller holes are just as restrictive as less, larger holes. Cutting out the whole grill and using the basic wire grills will be the best option, as they are the least restrictive grill. Sure, you could leave the grill off, but because there are small animals around my house that could get curious around that computer, I leave the grill there, and chase them away constantly. No need to take that sort of risk.

Beyond 1 meter, I would say my computer is inaudible. Sitting at my desk, with it tucked under, I would say the only audible thing is the raptor crunching away. Any ambient noise, be it an open window, someone else talking, or music playing.

The fans are all soft mounted, even on the CPU heatsink, there are rubber corners which I have on the NMB fan on the Ninja, the exhaust fan uses rubber fan grommets, and the fan on the accelero is mounted with some extra hang space with twist ties.

Without going through a lot of trouble, it would be hard to get my computer much quieter than it is (or completely silent).

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