Power requirements for PCIe boards today?

[Jim Bancroft]

There's been some discussion about what sort of PS you need to run a PCIe system. Does anyone know what the guidelines are for Socket 939 mobos w/PCIe and say, a GeForce 6600GT or X800 card? Is 400 Watts/18A going to do it? 450W? Let's take overclocking out of the equation for a moment and assume stock speeds on everything.

I know SLI setups are a different story-- and what about those? 500 watts+ or forget it?

 

[ts3433]

SLI: Probably ~30A on the +12V rail.
One PCIe: ~20-22A on the +12V for starters, possibly a little more, I'd think.

 

[Dethfrumbelo]

It depends on how much other stuff you've got in there, and which brand of mobo.

20A on the 12V line should be adequate for a 1 video card system with 2-3 HDs. Many PSU manufacturers are deceptive about their ratings. They'll often list peak current/power and not continuous in their specs. Try doing a P = IV (Power = Current x Voltage) on their specs and see if it really adds up to what they're claiming.

Raw amps are not the end-all to running a stable system either. Look for a PSU with low ripple and noise.

 

[gobucks]

personally, i'd get a nice 24-pin PSU, since most PCIe boards now use them. You can use 20-pins, but for an SLI setup, mobo makers are STRONGLY suggesting a 24-pin PSU. Even Asus, who has a 4-pin connector just for the PCIe slots (their EZ-Plug) says not to use a 20-pin PSU for anything higher than an SLI 6600GT setup. I got the Vantec Stealth VAN-520A and like it a lot, i've also heard good things about the Enermax and Antec 24-pin PSUs. Mine was $92, the other ones i've mentioned can run up to $150.

 

[o1die]

I recommend sparkle/fortron power supplies. They typically peak at 18 amps on the 12v rail, but are also underated some for peak loads. My lowly 300w is overclocking a 2.8c at 3640 (30%). I like the 12cm models with single large side fan for drawing the heat away from the cpu.

 

[Jim Bancroft]

So you're using a 300W power supply with no trouble? I guess my 400 should be ok then....I just went to Gigabyte's website and looked up the specs on their nforce 4X board. The manual talks about a 300 watt power supply being the minimum, but I couldn't find any amperage minimums, so I guess 18 amps should work?

 

[najames]

I just built a MSI Neo2 Platinum socket 939 (AGP, PCI) board, nothing fancy. AMD spec called for 300w minimum PSU, altough Shuttle SFF factors use 240w PSU.

I have a Thermaltake Silent PurePower, 420W form Newegg, $36 free shipping, works great. Slightly overvolts on 3.3v and 5v, 11.91 on 12v line according to bios. It comes with a 24pin and other adaptors. I am considering another for second build.

http://www.newegg.com/app/View...=17-153-006&depa=0

I also have a good spare Fortron 300w similar to link below that will likely work well too for basic systems as o1die said. I'd buy above Thermaltake PSU if I wanted another one.

http://www.newegg.com/app/View...=17-104-937&depa=0

This is an old/good PSU article. Is it a wonder those FSP300-60ATV PSUs hold up well?

http://www.tomshardware.com/ho.../powersupplies-01.html