#### General FAQ ####

PSUs: The source of DC power for all components in the PC & often a big noise source.

Moderators: NeilBlanchard, Ralf Hutter, sthayashi, Lawrence Lee, Devonavar

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sthayashi
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#### General FAQ ####

Post by sthayashi » Sun Jul 11, 2004 8:31 pm

This FAQ is an attempt to reduce the level of repetitive traffic in the SPCR forums. Most of these questions can be answered by looking at the recommended pages or searching the forums. Sometimes though, there are no clear answers and I hope that this FAQ will help clarify these types of questions as well.

Q: Can someone recommend me a good (heatsink/powersupply/case/fan/hard drive)?
A: Yes.

Q: Is this a good (heatsink/powersupply/case/fan/hard drive) [On the recommended list]?
A: Well what do YOU think? (i.e. If we recommend it, then we think it's a good product).

Q: Is this a good (heatsink/powersupply/case/fan/hard drive) [NOT on the recommended list]?
A: This is a much trickier answer. Sometimes, there's a product out that none of us have really had a chance to try out. Do a search to find out. If there are results, then READ them and find out what the deal is. Chances are, it's one of four things:
1) It's NOT good for silent computing.
2) It's alright, but some people have had some issues and/or there are better choices.
3) It's great, but since the SPCR staff hasn't had a chance to formally review it, it hasn't made the recommended lists (or it's been reviewed more recently than the last recommended update).
4) No one knows.

Since there are usually a lot of tried and true choices out there, it's best not to get hung up on any one product that we haven't covered.

Keep in mind that although the SPCR community is global, the SPCR staff is primarily North American. So if there's a product that's not really available in North America (the Be Quiet! power supplies come immediately to mind), it probably won't be reviewed any time soon.

Q: Can someone recommend a quiet or silent >500W power supply?
A: Hold your horses there. Very very few people need a power supply that can put out 500W. On the Recommended Power Supplies pages, MikeC has painstakingly explained why bigger is not always better. Also on those pages is a listing of maximum power draw of typical PC setups. On THIS forum discussion, people have listed their systems that work fine with various PSUs rated at 300W. Chances are there is at least one system that looks a lot like the one you have or are considering.

Q: But I'm building an SLI system with a lot of different hard drives.
A: It's still the same deal. The most amount of power measured from a video card was 76W with the 6800 Ultra at full load with an over clock. Let's round that up to 80 for easier math. You'll get 160W from the video. Now the highest powered AMD processor on the market right now dissipates a maximum of 89W. So between your video cards and processor, you're drawing 250W. Hard drives draw not much more than 30W when they spin up, but once spinning, they only draw about 10W each. That's about it. Most of the other accessories like Sound Card, Ethernet, draw at most 10W and far more likely, just 1W if even that. So with a 6800 Ultra SLI system plus 4 hard drives, you're drawing maybe around 300W total. And if you're actually using 6800GT, drop about 20W per video card, or 260W total. Still think you need a 500W power supply?

If you're STILL not convinced, do the math yourself. I use this source for processor draw, and X-bit lab's article for video power draw. Doing the math yourself is a good idea anyways, especially if you intend to overclock.

Q: Alright, you've convinced me that my system doesn't draw 300W, but my system is unstable and I'm pretty sure it's the power supply. I'm running an Athlon 64/Pentium 4 and an older recommended PSU.
A: This has happened once or twice before. The latest family of processors from AMD and Intel require more power from 12V than before. Previously, most of the processor power was drawn from 5V. Well our older recommendations reflect that and are a little weak at 12V. For example, the Nexus NX-3000, a 300W power supply was only capable of supplying 15A on the 12v line. This corresponds to 180W at 12v. So it's entirely possible that your setup draws less than 300W, but is too powerful for your power supply.

All of the power supply reviews mention the current ratings on each line, often right there on the first page.

Q: My Voltage lines are low/high. Wasn't this was a recommended power supply?
A: First, are they even worriably low? 5% +/- is the general rule. This means you shouldn't be a concerned if it's within the following ranges:
1) 3.14-3.47v
2) 4.75-5.25v
3) 11.4-12.6

Second, have you ACTUALLY measured the voltage with a multimeter? The on-board motherboard voltage sensors are notoriously unreliable in this regard.

Third, is it causing any problems? Many people worry about numbers that they see from their reporting tools, but forget that their system is more or less rock solid.

If you've answered yes to all three of the questions above, then you probably do have a problematic power supply, which may be the only thing we can tell you.

Q: Is this <insert recommended PSU here> good enough for my system?
A: Maybe. Most of the recommended PSUs have been discussed in the past. Between this FAQ page, the links on it, and a search of the product in question, you can answer this question as good (if not better than we can). NOTE: We get this question A LOT. If you ask this question and it's clear you haven't looked for the information first, your thread will be locked.

Q: Can SPCR review this (heatsink/powersupply/case/fan/hard drive)?
A: Yes. We don't generally buy samples but rely on donations from users and contributions from sponsoring retailers and companies. If you would like to see a product here on SPCR, don't write to MikeC. Write to the company and/or its distributors and ask if they would send a sample to SPCR for review. Or read what MikeC suggests.

Q: Can someone recommend me a retailer that sells silent PC parts in Canada/UK/Australia?
A: Many SPCR members are from Canada, UK, and Australia, and have posted threads on stores that sell silent PC parts in their respective countries. There are some products that are not easily available outside the United States (like Sorbothane). Unfortunately, there's little one can do about it. Your best bet is to make an offer, but be sure to do that in the proper forum.

Q: There's a question that ought to be in the FAQ. Why haven't you answered it?
A: As much as I hate to admit it, I don't know everything about silent PCs. I'll be happy to add your question to this FAQ if you can post both the question and answer to this thread.
Last edited by sthayashi on Wed Jul 14, 2004 5:10 am, edited 2 times in total.

sthayashi
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Post by sthayashi » Fri Mar 04, 2005 2:23 pm

Updated with 3 NEW questions.

UPDATED QUESTIONS:
Q: Can someone recommend a quiet or silent >500W power supply?
Q: But I'm building an SLI system with a lot of different hard drives.
Q: Alright, you've convinced me that my system doesn't draw 300W, but my system is unstable and I'm pretty sure it's the power supply. I'm running an Athlon 64/Pentium 4 and an older recommended PSU.
Q: My Voltage lines are low/high. Wasn't this was a recommended power supply?

Feel free to quote portions of this FAQ to people who ask.
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jamesm
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Post by jamesm » Thu Jun 02, 2005 11:21 pm

what's the deal with the 24 pin connectors?

Devonavar
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Post by Devonavar » Fri Jun 03, 2005 10:33 am

jamesm wrote:what's the deal with the 24 pin connectors?
The 24-pin connector was introduced as a way to provide the needed power for the PCI-Express bus when it first debuted. All modern ATX12V 2.x power supplies come with the 24-pin connector, but there's still quite a few older ATX12V 1.3 PSUs on the market that ship with the 20-pin connector. In most cases, a simple adaptor is all that's needed to convert from 20 to 24 pins or vice versa. Many 24-pin motherboards will still work using only the 20-pin connector, although they are supposed to be more stable with the 24-pin connector, especially with a powerful PCI-e VGA card.

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Post by GentleGiant » Wed Feb 15, 2006 2:53 pm

Tell me more about -5V output and motherboards that require it.

I have a new GA-K8N51PVMT-9 Gigabyte motherboard (s939/nForce 430/GeForce 6150) which Antec tells me is not compatible with their power supplies because it requires -5V, which has disappeared from ATX 2.x standards.

What power supplies are available with lots of 12V power that still provide -5V?

Devonavar
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Post by Devonavar » Wed Feb 15, 2006 3:41 pm

Allow me to call BS on Antec for this one. I have yet to encounter a modern board that requires -5V. I've only seen one report of such a motherboard, and that was on a K7 board that was manufactured before Intel updated the ATX12V spec. Find a different PSU, but don't worry about -5V.

jaganath
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Post by jaganath » Wed Feb 15, 2006 4:14 pm

Allow me to call BS on Antec for this one
Does anyone else find Antec covering up real flaws in their product with fake incompatibilities more than a little reprehensible?

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Post by justblair » Wed Feb 15, 2006 4:18 pm

Dont know about mobo's, but if you want to run a VFD display on your HTPC you need a -5v line. I dont want to see them dispapear. I want to use these displays when the costs come down on them.
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TomZ
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Post by TomZ » Wed Feb 15, 2006 4:25 pm

Does anyone else find Antec covering up real flaws in their product with fake incompatibilities more than a little reprehensible?
First, Antec shouldn't be having these sorts of problems in the first place. They have been successful enough in the marketplace to be able to afford to invest in good quality control processes/procedure. Clearly these products have design flaws that were not uncovered until they had product in the field.

Second, Antec seem to be doing a bad job of handling the problems that are arising. They make excuses, give sketchy and possibly incorrect information about what is wrong, and treat customer complaints like one-offs.

The issues with Antec are all over the 'net - in forums like this and in user reviews at Antec reseller web sites. They need to get their act together and get "real" about what is going on.

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Post by smilingcrow » Mon Jul 03, 2006 12:26 am

Devonavar wrote:In most cases, a simple adaptor is all that's needed to convert from 20 to 24 pins or vice versa. Many 24-pin motherboards will still work using only the 20-pin connector, although they are supposed to be more stable with the 24-pin connector, especially with a powerful PCI-e VGA card.
When you say, ‘in most cases, a simple adaptor is all that is needed’, is it possible to be specific about which situations will cause problems?
Are the extra 4 pins purely for delivering power to the PCIe 16X slot(s)?

I have a 20 pin P/S and my next motherboard will no doubt be 24 pin; since I’m thinking of using a 7600GS or GT in it, I’m wondering if I’ll need a new P/S or can likely get away with an adaptor.

nici
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Post by nici » Mon Jul 03, 2006 2:15 am

It should work just fine, my DFI nF4 works with a 20-pin psu with an x800XL and x800GTO, and i know the A8N-SLI Deluxe also works with a 20-pin and a 6600GT. That´s without any adapters, just four empty holes on the mobo.

Ant6n
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4-pin

Post by Ant6n » Sat Nov 11, 2006 11:48 pm

What's the deal with the secondary 4-pin vcore connector?
(i.e. are they needed; can i run my athlon64 system with the 24 pins the adapter from my 20 pin psu supplies)
Last edited by Ant6n on Sun Nov 12, 2006 2:31 pm, edited 1 time in total.

Devonavar
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Post by Devonavar » Sun Nov 12, 2006 1:56 pm

Are you talking about the separate 4-pin connector with two yellow wires and two black ones? Yes, that one is certainly needed; it powers the CPU.

If you're talking about the extra four pins in the on the main ATX connector; it is usually possible to power a system that has a 24 pin connector with a 20 pin plug (no adaptor required).

Ant6n
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Post by Ant6n » Sun Nov 12, 2006 2:51 pm

Ok, so how does one get this secondary 4pin power supply (with the yellow and black lines) if one uses a 20pin supply?
(i think this is relevant as general faq, because some of the quiet psu's, i.e. picopsu, should be able to power "normal" systems)
EDIT: found it, googling "Pentium 4 12 Volt ATX Adapter Cable" does the trick, i hope this will revive my dead system

mike86
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Re: #### General FAQ ####

Post by mike86 » Fri Jun 01, 2007 2:28 pm

sthayashi wrote:Q: Can SPCR review this (heatsink/powersupply/case/fan/hard drive)?
A: Yes. We don't generally buy samples but rely on donations from users and contributions from sponsoring retailers and companies. If you would like to see a product here on SPCR, don't write to MikeC. Write to the company and/or its distributors and ask if they would send a sample to SPCR for review. Or read what MikeC suggests.
That link is broken.

michaelhoffman
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Post by michaelhoffman » Sun Nov 15, 2009 9:32 pm

Hi sthayashi,
You have mostly covered the frequently asked question in your comment. You would have done the hard work for this. It's really appreciable. If everybody follows it properly, I am sure that the traffic on the forums would be controlled. I will surely send you some queries with their answers in regards to the same topic, so that you can admit in this forum.
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