Dedicating a GPU to PhysX

[fn_Quiksilver 1633]

Just purchased a GTX 660 (2gb).

Now I have a GTX 650 (1gb) collecting dust.

I was told that I couldn't run those two cards in SLi, but that I could run both cards and have one dedicated to PhysX.

Is that possible with the above?

Does it work with ArmA?

[dayglow 2]

Arma uses CPU PhysX. No gain from running a dedicated GPU PhysX.

[MavericK96 0]

Yep. Sadly, no benefit for ArmA 3 with that setup.

I would try to sell the 650 and buy another 660 for SLI if you want to go multi-GPU.

[kremator 1064]

We need the option (if we have a PhysX capable card) to push the PhysX to that card from CPU!

[metalcraze 290]

Dwarden said they don't want to screw the other 50% of players without GeForces. I still cannot understand how exactly utilizing NVidia hardware to its fullest (while also providing PhysX effects that a CPU won't handle) screws anyone.

Laziness sounds like a much more viable explanation.

[kklownboy 43]

Dwarden said they don't want to screw the other 50% of players without GeForces. I still cannot understand how exactly utilizing NVidia hardware to its fullest (while also providing PhysX effects that a CPU won't handle) screws anyone.

Laziness sounds like a much more viable explanation.

the CPU can handle all physX effects, and should... Nvida off loads to the CPU anyways.

[A. GrayFOX 10]

well they are screwing nvidia users already with reduced performance.

[MavericK96 0]

I honestly don't think PhysX has much to do with the bad performance (yet). It's more of a utilization issue present since ArmA 2.

[frostwyrm333 1]

Since Arma 3 isn't using any performance heavy physics or effects its not that important.

[dayglow 2]

Dwarden said they don't want to screw the other 50% of players without GeForces. I still cannot understand how exactly utilizing NVidia hardware to its fullest (while also providing PhysX effects that a CPU won't handle) screws anyone.

Laziness sounds like a much more viable explanation.

Laziness? Do you really think it's as simple as use_GPU=1?

amazing. :j:

[Ekko 1]

Laziness? Do you really think it's as simple as use_GPU=1?

amazing. :j:

Well, correct me if I am completely wrong, but I think others have been able to do it before...

But then again, this is the RV engine, so do lose the hope.

[metalcraze 290]

Since Arma 3 isn't using any performance heavy physics or effects its not that important.

Ballistics can be made CUDA/PhysX dependent and that thing is heavier on a CPU than AI.

Plus even the stuff already there. Like a breaking glass which simply clips through the ground and disappears instead of the same effect that will have much higher quality (more particles), a glass that can drop and stay on the ground and then disappear smoothly instead of clipping and looking bad - and all that will be much lighter on a GPU than what we have now on a CPU.

It isn't like PhysX will give anyone some kind of unfair advantage. It will just make the game look nicer at least and possibly even run faster. Considering ArmA performance demands BIS should consider every option, even if it's just for users of one of manufacturers.

Laziness? Do you really think it's as simple as use_GPU=1?

amazing. :j:

Yes utilizing GPU PhysX is so amazingly hard no games have it. Especially not those built with an industry-standard Unreal Engine.

Adding CPU PhysX is ok but GPU PhysX? No that's rocket science.

Edited October 16, 2013 by metalcraze

[fn_Quiksilver 1633]

So basically, there is no benefit (for Arma) to keep my 650?

[dayglow 2]

Ballistics can be made CUDA/PhysX dependent and that thing is heavier on a CPU than AI.

Plus even the stuff already there. Like a breaking glass which simply clips through the ground and disappears instead of the same effect that will have much higher quality (more particles), a glass that can drop and stay on the ground and then disappear smoothly instead of clipping and looking bad - and all that will be much lighter on a GPU than what we have now on a CPU.

It isn't like PhysX will give anyone some kind of unfair advantage. It will just make the game look nicer at least and possibly even run faster. Considering ArmA performance demands BIS should consider every option, even if it's just for users of one of manufacturers.

Yes utilizing GPU PhysX is so amazingly hard no games have it. Especially not those built with an industry-standard Unreal Engine.

Adding CPU PhysX is ok but GPU PhysX? No that's rocket science.

BI choose physx as their API for physics. Would Havok or some other solution been better? I have no idea. The GPU side adds particle ant smoke effects. You say it's lazy I'd say its proper time management to not spend time on pure visual effects that maybe half players will see. 10 to 1 you'd be complaining that they wasted all the time on pretty particle effects instead of fixing the core game if they did take advantage of the GPU anyways.

The fact that you haven't created a better game than Arma is a sign of your laziness

[fn_Quiksilver 1633]

The fact that you haven't created a better game than Arma is a sign of your laziness

This is a common tactic in an attempt to stifle criticism.

[dayglow 2]

This is a common tactic in an attempt to stifle criticism.

No it's a comment that makes as much sense as his accusation of the BI devs being lazy for not implementing gpu PhysX.

[DaRkL3AD3R 1]

Laziness? Do you really think it's as simple as use_GPU=1?

amazing. :j:

If they're using the PhysX SDK... it almost is =/

[Pyrophosphate 1]

Particles are almost the only things that actually run faster on a GPU. That's why games that use GPU PhysX basically make a big particle mess and that's it. Any kind of actual physics intended to be used in the game requires that data travel both ways over the PCI lanes, and the incoming data then needs to be reintegrated into the game state. That all takes more time than simply doing the work on the CPU.

Ballistics (especially), simple vehicle physics, and ragdolls are all faster on the CPU, even with the rest of the game running next to it.

[Polygon 11]

How about we understand that different engines have diff. architectures? RV isn't similar to UE that mostly utilizes corridor gameplay with many splosions on screen.

For exampke, 4a engine (Metro games) utilizes Physx nicely for eye-candy, but it's also a corridor shooter.

Anything that requires interaction must be passed to CPU otherwise the game-world won't be affected. I suspect putting interactive calculation to GPU doesn't work because GPU, upon calculating on its own, must transfer results back to CPU.

[dmarkwick 261]

This is a common tactic in an attempt to stifle criticism.

When the criticism takes the form "the devs are lazy" I think it's a reasonable response. Particularly when those same people have no contribution other than complaints.

[-=seany=- 5]

I would really hope that the reason that Arma3 does not have the ability to use GPU based PhysX processing is not beacuse 50% of the people might feel left out...I also doubt it would be that hard to enable. I'll just hope that there is an actual legitimate reason.

[dmarkwick 261]

I would really hope that the reason that Arma3 does not have the ability to use GPU based PhysX processing is not beacuse 50% of the people might feel left out...I also doubt it would be that hard to enable. I'll just hope that there is an actual legitimate reason.

The reason is that for the most part GPU PhysyX is more concerned with eyecandy fluff, like flapping cloth, small fragments, stuff that is client-side only. For PhysX that requires vehicle collisions, especially across MP, it's CPU only.

[neokika 62]

PhysX particles are being looked at. But it is not something that can be done from night to day, needs Program, Art and Design time/effort. :)

[-=seany=- 5]

Good to know neokika, thanks for replying :)

Thank's too DMarkwick, that does sound familiar.