nVidia GeFORCE GS8400 vs. 650W PSU

[[F|H]NitroViper007]

Okay guys, I really need some good professional help on this one, I need to know if a 650W would run a nVidia GeFORCE 8400GS 256MB graphics card on a 650W power supply along with the other components I have installed without blowing them up or under-powering them, I know there are some real experts on these forums so if you could help me then please do, my +12V rail is 25A peak if that means anything.

Thanks alot in advance,

[F|H]NitroViper007

[VoXiNaTiOn]

I run a GTX280 on a 650W PSU, so an 8400GS will run easily.

You could probably get away with a 450W or something.

[FuzzySquirrel]

I heard of people running a 9600GT on a 250w psu...

[boom50cal]

I could run my soon to be 9400 GT on my 280W but I'm getting something better soon. Maybe a 500W but most likely a 350W or 400W. Power cost's are up quite a bit.

Heck you could run that 8400 GS with another one of those or possibly an 8800 GT..

[erfrag]

its not the watts its the amps.

500 should be fine if it is a half descent unit. you want as many amps on the 12v rail as possible (preferably 1 12v rail).

25A on the 12v is plenty but it sounds like a kind of weak/bargin-bin/generic PSU. for example my 500 watt has 38A on the 12 (2x24A, 38A because power does not scale 100%). it might also help to know what your "other components" are as well.

keep this in mind: your PSU only has 288 watts on the 12v rail (12v x 24A). mine has 450watts (38A x 12v). 288watts on the 12v rail also means that you have more 5v and 3.3v than you could ever need. 12v is what is important in todays world. i look at it as you buy the PSU for the 12v, the 3.3v and 5v are just icing on the cake.

for the past 6 years a high end CPU draws ~100watts (8-10A). high end graphics >100watts (10A) for single cards. all drawing from the 12V rail.

If it helps an OC'd core i7 system with a GTX260 pulls <400 watts from the wall under load, and with a GTX295 system it pulls around 500 watts..... balls to the wall a GTX260 system spikes out around 25A on the 12v rail and 3-4A, possible 5 or 6A on the 3.3v and 5v rails...

[AquaticPenguin]

I run a 8600gt fine on a good quality 250 watt PSU so 650w is a bit overkill I think

[Tofurkeymeister]

I'd just like to add that higher wattage PSU's do NOT use more power. They are simply capable of providing more if need be.

[MonkeySoldier]

You use a 650 Watt PSU (I'm talking a high quality one) to run GTX 260 (216)'s in SLI or HD 4870's in CF, but not for a 8400GS. The TDP of a 8400GS is 30 W. So I'd recommend getting something like a 350 W high quality PSU.