Physx performance

[ThaJollyMan]

I was just wondering...how good would performance be if you were to run , lets just say, 2 9800 gtx's in sli and have a 9800 gt as a dedicated physx card. If anyone has a link to site with this type of review that would be great. Also, how much of a performance difference would there be between a 9800 gt and an 8800 gt, in terms of physx processing?

 

[aka1nas]

You need to look one thread down.

 

[cmdrdredd]

Originally posted by: aka1nas
You need to look one thread down.

There was no SLI test.

 

[SSChevy2001]

It would be too CPU bottleneck to have both SLI and a dedicated physx card.

This links clearly shows how a single GTX280 will do just fine for both rendering and physx.
http://www.firingsquad.com/har..._performance/page8.asp

 

[ThaJollyMan]

Well from one review that i read when you run 1 gpu separately for graphics and the other for physics, you get better performance than if you were to run physx and graphics on one card.

With gtx 280 and 9600 gt -------> http://guru3d.com/article/physx-by-nvidia-review/4

I havent been able to find a review where someone is running SLi and a separate card for physics.

 

[SSChevy2001]

Originally posted by: ThaJollyMan
Well from one review that i read when you run 1 gpu separately for graphics and the other for physics, you get better performance than if you were to run physx and graphics on one card.

With gtx 280 and 9600 gt -------> http://guru3d.com/article/physx-by-nvidia-review/4

I havent been able to find a review where someone is running SLi and a separate card for physics.

I haven't seen such a review also, but to be honest I don't think it's worth the extra idle power just to add another video card just for PhysX. Most cases a single GTX280 keep electric bill down without impacting FPS in Physx much.

Right now it's still to early to be investing in PhysX, just wait till some games are released to see how performance will be impacted, besides by then cards will be cheaper. Also the Big Bang II drivers are coming soon which might improve performance in PhysX with a single card.

In our test case today we used an nForce 680i mainboard with a 3.0 GHz Core 2 Duo processor, a GeForce GTX 280 and a GeForce 9600 GT. Our maximum wattage peak (system wide) measured from the wall socket outlet was a hefty 432 Watt, so that's really a lot. With a higher end graphics card you'd be able to use PhysX and rendering on the same GPU. So that would be the more power efficient way to go.

432 Watt is as much power as a 4870x2, also the idle power would be lower on the 4870x2

 

[aka1nas]

Originally posted by: cmdrdredd

Originally posted by: aka1nas
You need to look one thread down.

There was no SLI test.

Sorry, misread the OP. SLI + a 3rd GPU for PhysX is not supported yet.

 

[cmdrdredd]

Originally posted by: aka1nas

Originally posted by: cmdrdredd

Originally posted by: aka1nas
You need to look one thread down.

There was no SLI test.

Sorry, misread the OP. SLI + a 3rd GPU for PhysX is not supported yet.

Which defeats the purpose of running SLI IMO. All the power to push the FPS up and then you suck it back down with physx that adds no game play changes, just some object bouncing. *shrug*

Anyway, they need to get on that. I'd be much happier personally to dedicate one card for physx and the SLI dedicated for everything else.

 

[aka1nas]

Originally posted by: cmdrdredd

Originally posted by: aka1nas

Originally posted by: cmdrdredd

Originally posted by: aka1nas
You need to look one thread down.

There was no SLI test.

Sorry, misread the OP. SLI + a 3rd GPU for PhysX is not supported yet.

Which defeats the purpose of running SLI IMO. All the power to push the FPS up and then you suck it back down with physx that adds no game play changes, just some object bouncing. *shrug*

Anyway, they need to get on that. I'd be much happier personally to dedicate one card for physx and the SLI dedicated for everything else.

IIRC, it's most just an SLI support issue as the driver freaks out and will not show the "Enable SLI" option when a 3rd card is present(Excepting Tri or Quad-SLI capable configs).

There is a workaround that some people use for multi-monitor + SLI setups that involves disabling the third card in the device manager, enabling SLI, and then re-enabling the third card, but it's unfortunately not playing nice the GPU PhysX option in the Ageia CP applet.