400W to power a 400W+ card

nVital

I think I read if the 12V rail has high enough amps the 400W can power a beefy single gfx card. Lets say 400W with a 30A 12V rail, is this enough to power a 460W card?

Cheers

lmimmfn

not necessarily, do you mean a decent PSU capable of sustained 400W or a PSU with a max of 400W?

If you look at this chart - http://mark.zoomcities.com/images/gfx/GFXpowerchartbybrandgen.png

An Nvidia 460 uses 216W( i.e. needs about 18 amps on its own ) on 100% load with no overclock, so you've 180W to spare( on a decent PSU, if its a POS youve about 130W to spare ), can be done but can be tight depending on the cpu you intend to use with it

Solitaire

Broken link is broken. And that sounds too high even for a GTX460+ (or "GS" - 1GB versions, almost always on higher clocks), the GTX460 (768MB) use less than a HD5850 (much less a HD5830!) and should do fine with 10-12A IIRC

lmimmfn

Solitaire wrote: »

Broken link is broken. And that sounds too high even for a GTX460+ (or "GS" - 1GB versions, almost always on higher clocks), the GTX460 (768MB) use less than a HD5850 (much less a HD5830!) and should do fine with 10-12A IIRC

sorry, guess they dont like direct linking - http://forums.atomicmpc.com.au/index.php?showtopic=264

Solitaire

I've had issues with that chart before - some of the peak results are way off in la-la-land (~140W for a stock HD4830? Fail.)

Ironically, even then the peak 1GB OCd results barely crest 200W... As I thought, 768MB version is around the HD4850 area for hungries

lmimmfn

Solitaire wrote: »

I've had issues with that chart before - some of the peak results are way off in la-la-land (~140W for a stock HD4830? Fail.)

Ironically, even then the peak 1GB OCd results barely crest 200W... As I thought, 768MB version is around the HD4850 area for hungries

nah, i agree, but at the same time its the only chart out there to cover most gpus and without researching each and every one its impossible to tell.

I never like cutting it close on power though, value my components too much.

nVital

lmimmfn wrote: »

do you mean a decent PSU capable of sustained 400W

Crosair CX400W

Solitaire

I guessed from the 30A

Personally, its a bit tight, and if you have a 95-125W CPU in there I'd far rather go for a decent 450-500W model for the 768MB version, and a 550W PSU for the 1GB version (those also have higher clock speeds and an extra render back-end, so they suck quite a bit more juice! )

If you had the 768MB version and a stock- or light-OC (<+30% clock and no overvolt!!) 65-80W CPU (dualies) and only a basic system otherwise (no RAID array! ) you'd fit fairly well on a 30A rail, probably topping out 16-18A in intense gaming (titles that press both CPU and GPU hard) with the odd peak beyond that (especially in Crysis and OCCT; such spikes count against the PSU's 100% load limit instead of the 40-60% load preference as they are atypical). With a "low"-95W CPU (AMD tri-cores, i5-7xx) at or very near stock you could squeeze one in but it becomes less comfortable, with sustained loads reaching and possibly slightly exceeding 20A.

I wouldn't be comfortable running a 1GB GTX460, or any GTX460 either OCd over ~10% or with a "heavy"-95W (X4-945/i7-8xx) or higher-TDP CPU(or a heavily OCd X3/i3/i5) on any rig with 30A or less capacity - time to head for the 40A hills of 500W+ PSUs!