PSU for GTX480 sli + GTX280 physx?

[jbh545]

Vsync doesn't stop frames from being rendered, it just prevents them from being sent to the screen. If anything, the load is increased slightly.

That doesn't match my experience at all. With vsynch turned on with my 5970+5870 setup, card usage percentage and temperatures are both much lower. Like a game may stress the gpus 80% with vsynch off and 40% with vsynch on. I would assume that with the lower temperatures also comes lower power draw.

 

[scooterlibby]

To the OP - how did the 5970 + 5870 scale? Are you able to overclock all 3 GPU's simultaneously?

I am thinking about doing tri-fire when the Sandybridge/Bulldozer era comes about.

 

[MarcVenice]

To answer your question, I've been able to draw 750W from the wall in a game. Dawn of War: Chaos Rising to be exact. In Far Cry 2 or Bad Company 2, powerdraw at the wall would be 650W most of time. Furmark took it up to 800W. Assuming 750W is worst case, after efficiency, that's 637W.

Complete systemspecs: http://tweakers.net/reviews/1632/2/test-een-game-pc-met-twee-gtx480-kaarten-specificaties.html

So with that Corsair 1000HX, you're save in my book.

 

[Saga]

Out of curiosity (and not to intentionally de-rail) but on the subject of PhysX, does an 8800GTX make a good PhysX card or is it overkill?

 

[cbn]

I thought 300w/card was the max with 1 6pin + 1 8pin? (Probably wrong here)

At Guru3d, they were able to measure 380 watts power draw thru a 6pin and 8 pin when testing HD5970 @ 935Mhz core clocks.

 

[digitaldurandal]

Yeah broseph but are you being facetious or am I doing something genuinely risky in this specific situation? I also have a single slot 9800gt I could toss in for physx but that might actually slow down the system from what I understand.

The 9800gt will have the benefit of less heat and power and probably be perfect for Physx.

This also means you can sell or give away the 280. The 280 uses quite a bit of power and I definitely do not recommend using it for Physx alone. 9800gt will be fine for every Physx enabled game.

Honestly considering the sheer number of CUDA cores on the 480, it may be unnecessary at all. I am interested in seeing some benchmarks to see.

 

[digitaldurandal]

Out of curiosity (and not to intentionally de-rail) but on the subject of PhysX, does an 8800GTX make a good PhysX card or is it overkill?

I believe the 8 series does not support Physx.

 

[jbh545]

To the OP - how did the 5970 + 5870 scale? Are you able to overclock all 3 GPU's simultaneously?

I am thinking about doing tri-fire when the Sandybridge/Bulldozer era comes about.

The scaling is a mixed bag. Sometimes it was phenomenal, especially in benchmarks. Like on unigine tropics, 5970 oc was 2126 and adding the 5870 bumped it to a staggering 3582. Crysis at 1920x1200 also scaled really well. The problem I kept running into though is while they often post gaudy averages, they choke up where they shouldn't. This is probably the most extreme example:

However, there were a lot of games that stuttered when they shouldn't to a lesser degree. Everything from Hawx to Sacred 2. And Crysis Warhead was completely unplayable at 2560x1600 maxed out.

Overall the 5870 did help the play experience a lot. Plenty of games went from dipping below 60fps frequently to staying above 60fps at almost all time. It's probably the best setup for 1920x1200. If you play at 2560 though and you already have the 5970, a 5870 is worth the money if you get it for like $350. Just because it's worth the money doesn't mean it's optimal though. If the 2GB 5870s were priced more reasonably I'd have considered three of those, but as is I think the 480s are the better value. Not if you have to pay $550 for them, but at the $450 I paid they sure as hell are.

I actually searched forums very diligently before and after making this choice. I found one writeup a guy did testing a bunch of games on trifire vs 2x sli, and he echoed this, saying that the trifire could pump out better averages but the sli was smoother in most games with much better minimums.

As far as the OC goes, I've had 3 5970s because I flipped a couple on ebay back when they were $800+ because I really needed the cash and could go without the card for a while. Two of them did not have manual fan control and that hurts OC a lot. But you can still put the 5870 in the slot where the fan is blocked since it runs cooler and get some decent performance although temps will be in the 90s. The one I have right now has the manual fan control and it's no problem to set up profiles that keep all the cores mid to low 70s at 875/1200. They will be too loud without headphones though.

 

[Keysplayr]

I believe the 8 series does not support Physx.

Yes it does. Any 8 series or greater Nvidia card that has at least 32 shaders and 256MB discrete memory. So 8800GTX can run PhysX although there are better cards for this such as the OP's 9800GT.

 

[scooterlibby]

The scaling is a mixed bag. Sometimes it was phenomenal, especially in benchmarks. Like on unigine tropics, 5970 oc was 2126 and adding the 5870 bumped it to a staggering 3582. Crysis at 1920x1200 also scaled really well. The problem I kept running into though is while they often post gaudy averages, they choke up where they shouldn't. This is probably the most extreme example:

However, there were a lot of games that stuttered when they shouldn't to a lesser degree. Everything from Hawx to Sacred 2. And Crysis Warhead was completely unplayable at 2560x1600 maxed out.

Overall the 5870 did help the play experience a lot. Plenty of games went from dipping below 60fps frequently to staying above 60fps at almost all time. It's probably the best setup for 1920x1200. If you play at 2560 though and you already have the 5970, a 5870 is worth the money if you get it for like $350. Just because it's worth the money doesn't mean it's optimal though. If the 2GB 5870s were priced more reasonably I'd have considered three of those, but as is I think the 480s are the better value. Not if you have to pay $550 for them, but at the $450 I paid they sure as hell are.

I actually searched forums very diligently before and after making this choice. I found one writeup a guy did testing a bunch of games on trifire vs 2x sli, and he echoed this, saying that the trifire could pump out better averages but the sli was smoother in most games with much better minimums.

As far as the OC goes, I've had 3 5970s because I flipped a couple on ebay back when they were $800+ because I really needed the cash and could go without the card for a while. Two of them did not have manual fan control and that hurts OC a lot. But you can still put the 5870 in the slot where the fan is blocked since it runs cooler and get some decent performance although temps will be in the 90s. The one I have right now has the manual fan control and it's no problem to set up profiles that keep all the cores mid to low 70s at 875/1200. They will be too loud without headphones though.

Hey thanks for the detailed response! I appreciate it. I am just finding it funny that even with a juiced quad and 5970 the DX11 Ultra settings make Metro 2033 extremely choppy for my rig. Here's hoping Sandybridge + TriFire + DDR3 might let me smoothly play that game in all its visual glory