with two GTX 280 and a phyics card

[john19055]

how does that work .could you use a cheaper card just to run the physics part of the game.with two GTX280 and a 9800 for the physics.would I see a benifit or it that just possible on certain motherboads.Can you even run two GTX 280 in SLI and have a single card to run just the physics .would I see a performance in games or is the two GTX 280 powerful enough to do it all.I guess the simple question I am trying to ask is it woth while to do this.

[john19055]

If you have two GTX 280 running in SLI ,do you not need a phyics card.Or would a dedicated card help out,like a 9800gtx.Or would I not even see any help since I am running two GTX280 in SLI.

[ChrisRay]

The way Nvidia drivers work with SLI and identical cards and PhysX is.

1) SLI Enabled + PhysX enabled

First GPU does PhysX Workload + Rendering workload. Second GPU does all Rendering workload.

2) SLI Disabled

First GPU does rendering workload, Second GPU does physics workload.


If you were to add a 9800GTX to the mix.

You'd now have the option to set its own seperate PhysX device. Keep in mind this cannot be done with 3 identical cards due to the limitation of the driver currently. You will need an card with a different deviceID/type.

3) SLI cards do full rendering workload and 9800GTX does PhysX.

[john19055]

would putting a 9800GTX in there just for the physics be worth it ,like in the newer games.would I need a 512mb card or do I really need a 1gig card.would a 9800GT with 112 shaders and 512mb of memory be enough for the physics.what do you mean by the ID would a GTX 260 work.

[john19055]

Is there anyone here running two GTX 260's or two GTX 280's in SLI with another card running just the phyics.and was it a big help in games that used it.

[ChrisRay]

Using a 9800GTX as a PhysX card would depend greatly on the resolution your running. If you were doing 2560x1600 with 16xAA/16xAF and playing Mirrors edge. Having a 9800GTX + would benefit your performance a great deal. Physics processing does use GPU resources. So you need to consider your bottlenecks already.

[john19055]

I would be running it off a overclock i7 920 and a Gigabyte EX58-UD5 with 6 gigs of DDR3 1600 memory.I want be running at 2560x1600 since I just have a Dell 24" monitor.

[Anzial]

I think, in terms of physics 9800gtx doesn't offer much over 9800gt, there's just not that much load in physics only. 9600gt to 9800gt does yield some benefits, at least according to Firesquad

[ChrisRay]

Originally Posted by john19055

I would be running it off a overclock i7 920 and a Gigabyte EX58-UD5 with 6 gigs of DDR3 1600 memory.I want be running at 2560x1600 since I just have a Dell 24" monitor.

At that resolution you probably would see a benefit in Mirrors edge using a 9800GTX as a physx card.

[Sazar]

Originally Posted by ChrisRay

At that resolution you probably would see a benefit in Mirrors edge using a 9800GTX as a physx card.

Ohi Chris

*wave*

[john19055]

What is this Mirrors edge,a game.So a 9800 Gt would do just as good as a 9800GTX ,I am really looking for a single slot card.Plus do I need a 1gig card or would 512mb do just fine.

[john19055]

I now there has to be someone useing two GTX 260,280 or the 285 in SLI and useing a 9800GT or 9600GT for dedicated physics.Does the drivers support running 2 GTX 280 and a dedicated card just for the physics.I have looked at some reviews but they are not much help ,but from what I have seen a 9600GT is just as good as a 9800GT.