GPU to Run PhysX

[Yogi2367]

I am currently running a 4790K on a Asus Z97-A 3.1 Mobo with 32GB of RAM, mounted in a Cooler Master HAF 932. I'm driving a pair of GTX950's in SLI and dedicating PhysX to the CPU.
I would like to get the PhysX off the CPU and onto a card all its own and still keep the SLI. The problem is that I'm out of space in my case. The left most PCIE x3 slot is at the edge of the board and the edge of the board is up against the PSU leaving me only enough room for a single slot GPU. The only single slot Nvidia GPUs I can find are the GTX 750 and the GTX 750ti.
My question is would either of these cards do a better job with PhysX than the CPU, or should I just plain leave well enough alone?

 

[sizzling]

There is another consideration which I am not sure of the answer. The 4790k has 16 pcie lanes, when in sli these are shared 8x8 with each gpu instead of 16 for a single GPU. Adding a 3rd card may force sli to 4x4 and the 3rd card run at x4 too. You really need to find benchmarks as I fear you may actually decrease performance.

Also PhysX is so poorly supported and sli is not always supported I would look into selling both 950's and add the money you would spend on a 750Ti to getting a single stronger card. The more cards the more problems

 

[Wolfshadw]

I'm driving a pair of GTX950's in SLI

Please tell me that's a typo!

You are going to be hard pressed to find a decent single slot width card capable of running as a dedicated PhysX card. Personally, I wouldn't bother and just leave well enough alone.

-Wolf sends

 

[Onus]

Have you considered selling one of the GTX950s, using the remaining one for PhysX, and getting a GTX960 or GTX970? Just a thought; SLI sometimes has issues, especially with newer games.

Otherwise, I would expect a GTX750 to do better than a CPU for PhysX, but I don't know that it would be a huge difference unless your CPU is really loaded down and needs the help.

 

[delaro]

Why in the world would you run a 950 SLI? SLI in generally has issues but low end SLI is a Micro Stutterfest under demanding loads, lets not forget the constant breaking of SLI drivers with updates. What Onus suggested would be a better way to go, a Stronger Single card and a 950 for the PhysX.

 

[Yogi2367]

Thanks for the help guys ... just needed a cattle prod to the brain I guess.

@sizzling ... you're right PCIE lanes is an issue. The closest to the CPU and center slots are x16 and tied to the CPU. The slot farthest from the CPU is also x16 but tied to the chipset ... no good for GPUs.

@Wolfshadw ... no, it's not a typo ... LOL. Was waiting to see what Pascal brings to the table then decide on what to buy new. And yes, finding a single slot card is next to impossible. The only NVidia ones that I have found are the GTX 750's.

@Onus ... I'll repurpose the 950's into workstations and upgrade to either 980's or Pascal depending on performance value when Pascal is released. The CPU is not being loaded down at all. It easily runs an MMO game under Win 7 Pro native and 2 VM on Win 10 at the same time ... and no, there's no particular reason to run 3 instances of a game on three computers (1 native/2 VMs) at the same. I just do it because I can

@delaro ... because I already had the 950s. Besides, it actually runs quite well as SLI with PhysX on the CPU. I have yet to experience broken drivers, and I get zero stuttering.

 

[17seconds]

The main issue is running PhysX on the CPU. Put the setting on Auto in the Nvidia Control Panel and let your graphics cards handle it. Using the CPU in a GPU accelerated PhysX game will kill your performance.

Since you're saying that your performance is good using the CPU, I doubt you're actually playing a proper GPU accelerated PhysX game. Either that, or the game is only providing a basic effect level. So what PhysX games are you playing?

 

[Yogi2367]

You're probably right. The game is World of Tanks maxed out in HD mode. I'm not really sure it's PhysX or not.

 

[17seconds]

Not a GPU accelerated PhysX game. Borderlands 2/Prequel are the ones that really can test your hardware, particularly in battles outside where there's lots of particles flying around.

List of PhysX games:
www.physxinfo.com

You can always enable the "PhysX Visual Indicator" from within the Nvidia Control Panel to display which component is handling PhysX on screen during games.

 

[Yogi2367]

Ah, thanks ... I have Borderlands2/Prequel ... I run that maxed out as well ... no issues at all.
Thanks for the tip on the visual indicator