How close is too close

[Exterous]

Long story short - I was given a new GPU to run in SLI with my current one and a really nice Fatality sound card

Using the extreme PSU calculator I came to a total of 495w with the new stuff. Now my PSU is a 500w Antec NeoHE. Is this too close to the max to run safely?

Now, if I want to use this stuff - I do have a good 275w Hipro psu laying around not doing anything. Could I hook up some components to this PSU and have it work ok? I am guessing yes, but I am not sure of the downsides (other than mounting the PSU)

FYI - I don't currently have enough $ for a new PSU

Thanks guys

 

[rise]

welp, don't trust power calculators as they overestimate for vatious reasons. but that psu isn't sli cert'd so i'd want to know what gpu you're talking about. if its a high end card, you may be in trouble. well, not really as you have the 2nd supply.

 

[aka1nas]

The NeoHE is SLI certified, but not for the G80.

 

[Exterous]

7600gt

But its ok to use 2 psus?

 

[Modelworks]

Technically it is possible to use two supplies in one system.
The problem comes in that you really don't want to use the two supplies on something like a video card sli setup without knowing exactly where the power is going through the video cards. Its a very touchy thing.

PC power supplies are switch mode and monitor the output and then adjust the switching rates to match what they want at the output, depending on load, etc.

If you were to use one supply on each card you may run into a situation where one supply is merging with the others and the two supplies trying to match each others output. You could very well end up with oscillations that would destroy either supply or your video cards, etc.

You could also have a situation occur where the voltages produced are not correct because one supply is seeing the difference in the voltage of the other supply rather than the output voltage.

Its better that if you do use a second supply in a system that the voltages each supplies never come into contact with each other. Use it for fans, cd drive etc.

 

[Exterous]

Yeah - thats what I was planning on using it on. Its good to know that should work. Thank you

 

[rise]

Originally posted by: aka1nas
The NeoHE is SLI certified, but not for the G80.

i meant "rise sli-cert'd". lol.

i stand corrected.

 

[wbloon]

How about using the second PSU to supply hard drives?

My main PSU meets the recommended wattage for the mobo but I'm installing 7 HDs, 2 optical drives, and a fan controller with 4-5 fans. All that could draw about 100 watts and since I have 2 SLI cards I want to relieve the PSU of as much "off-mobo" load as possible. I don't plan on attaching the second PSU to the video cards.

 

[LOUISSSSS]

u want to sli 2 7600gt's? the antec neohe 500 should be fine