physx overlay bugged? always shows cpu and never gpu

[zoulztealer]

so yesterday i turned on that option in nvprofileinspector that displays the physx overlay indicator ingame.

even if physx is forced onto the gpu through nvcpl the overlay still displays physx is assigned to the cpu.

turns out this is quite old and noone ever really seemed to wonder:

https://www.nvidia.com/en-us/geforce/forums/off-topic/25/149411/how-do-i-turn-off-the-message-physx-cpu-at-the-to/

What is this PHYSX -> CPU on my screen?
by u/ItzDerock in 24hoursupport

i may be wrong but it seems that either the overlay is bugged or physx never even runs on the gpu.

i cant find any picture online that shows the overlay running off gpu.

 

[R-T-B]

You'd need a game that supports PhysX gpu. There are only a handful that do, and most are fairly old now.

 

[zoulztealer]

You'd need a game that supports PhysX gpu. There are only a handful that do, and most are fairly old now.

well ive tried with war thunder and insurgency. both use physx but still show cpu.

 

[R-T-B]

well ive tried with war thunder and insurgency. war thunder uses physx but still shows cpu.

War thunder is not gpu physx enabled.

List of games with hardware-accelerated PhysX support

Script error: No such module "SDcat". Script error: No such module "Unsubst". Script error: No such module "Unsubst". PhysX is an open-source physics engine that runs via GPU or PPU. As of 2016, approximately 40 games supported it.[1] PhysX Nvidia GameWorks Physics engine Middleware List of...

list.fandom.com

This lists gpu enabled games, as well as older ageia ppu physx games. As I said, it's a dying thing mostly on older titles.

 

[zoulztealer]

War thunder is not gpu physx enabled.

List of games with hardware-accelerated PhysX support

Script error: No such module "SDcat". Script error: No such module "Unsubst". Script error: No such module "Unsubst". PhysX is an open-source physics engine that runs via GPU or PPU. As of 2016, approximately 40 games supported it.[1] PhysX Nvidia GameWorks Physics engine Middleware List of...

list.fandom.com

This lists gpu enabled games, as well as older ageia ppu physx games. As I said, it's a dying thing mostly on older titles.

gotcha. thx.

 

[80251]

While some games still use PhysX (e.g. Metro Exodus) it seems like support for GPU accelerated PhysX has died off -- even if you set NVCP to use the GPU, it won't.

 

[ir_cow]

Now PhysX type stuff is done in Unreal and the rest from the CPU. Use to take a lot to of processing power back when you only had 1 core to share. It's a non-issue now.

 

[zoulztealer]

whats the point enforcing running physx off cpu when the majority of players (~75%) does indeed have a physx capable gpu?

why even still have the option in nvcpl?

why not give players the choice with ingame and nvcpl settings?

it sure doesnt look like physx is becoming less important and less demanding in modern games but on the contrary its becoming more demanding and more widely used.

force running physx off cpu without a choice even whilst a physx capable gpu is present is just beyond stupid.

 

[DemonicRyzen666]

The majorty of DX12 games cannot support GPU physX & are locked to cpu only (which probably why a lot games stutter) anymore because of the way the new lower API is used & also It gets in the way of mGPU supported games.
The answer is to use mainly DX11 games to test for GPu physX to be working. The Witch 3 Wild hunt is supposed to have a few areas that use it but I think it's only like 5 times in the whole game. The Witch 3 Wild hunt complete version with the raytracing is locked to cpu)

 

[80251]

I tested Metro: Last Light w/dedicated GPU's for PhysX (a GTX 780 w/a 980ti, the 980ti w/a 1080ti), the only noticeable difference was more framerate fluctuation when using the 980ti as a dedicated PhysX accelerator.

Running PhysX on my 4090 the Metro: Last Light graph looked like this:

Running the Metro Last Light benchmark w/the CPU looked like this:

 

[ir_cow]

Physx fur is CPU only btw. That's used in Witcher 3

 

[zoulztealer]

I tested Metro: Last Light w/dedicated GPU's for PhysX (a GTX 780 w/a 980ti, the 980ti w/a 1080ti), the only noticeable difference was more framerate fluctuation when using the 980ti as a dedicated PhysX accelerator.

epic. you have some numbers for this chart too like peak and average fps / frametimes etc? did you "feel" any difference / improvement having it gpu bound? it looks like having it gpu bound is even contrary to performance and there are more dips visible into the lows while cpu bound chart looks way better and consistent.

 

[ir_cow]

I remember this being an issue in the past that if use a dedicated physx accelerator, It has to be equally or better than the graphics card used for rendering or you get frame spikes like that.

 

[80251]

Here's some of my observations when using a dedicated PhysX GPU w/Metro: Last Light:

I only saw a a peak of 33% GPU usage with my GTX 780 as a dedicated physX card with the 980ti -- it didn't even boost to the maximum core clocks and I had a custom tailored VBIOS.

When using a 980ti (once again with a custom VBIOS) as a dedicated PhysX accelerator w/my 1080ti I observed the following:

45° peak temp, 14% peak GPU load, mem. cntrllr load = video engine load = 0 peak, bus interface load = 0.6%, memory usage dedicated 168 MiB, memory usage dynamic 43 MiB,
power consumption 21.3% TDP, boosted to 1000 MHz. from 135 MHz.

It was basically a waste of power.

 

[zoulztealer]

Here's some of my observations when using a dedicated PhysX GPU w/Metro: Last Light:

I only saw a a peak of 33% GPU usage with my GTX 780 as a dedicated physX card with the 980ti -- it didn't even boost to the maximum core clocks and I had a custom tailored VBIOS.

When using a 980ti (once again with a custom VBIOS) as a dedicated PhysX accelerator w/my 1080ti I observed the following:

45° peak temp, 14% peak GPU load, mem. cntrllr load = video engine load = 0 peak, bus interface load = 0.6%, memory usage dedicated 168 MiB, memory usage dynamic 43 MiB,
power consumption 21.3% TDP, boosted to 1000 MHz. from 135 MHz.

It was basically a waste of power.

ah, so you are using multiple gpus at the same time. interesting.

 

[DemonicRyzen666]

I was trying to think of a better game than Metro, that uses GPU physic to the but the only games that came to mind were the Batman Arkham games.
Batman Arkham Asylum
Batman Arkham City
Batman Arkham knights
Batman Arkham origins

 

[80251]

@DemonicRyzen666
The number of GPU accelerated PhysX titles seems to be pretty small, even though I seem to remember it was about 2 dozen.

Did Fallout 4 use GPU accelerated PhysX? I think it only used it for particle physics (i.e. as when shooting at something or blowing something up).

I think Metro:Last Light might have been the game title that made the most use of GPU accelerated PhysX in that it used particle physics, cloth physics and smoke/fog physics. The smoke/fog physics effects were quite nice. If you walked thru floor fog, it would part and then reform behind you.

 

[Deleted member 182555]

some time ago I tried Batman Arkham knights with gtx 750ti 2gb oc + k620 2gb oc dedicated for physx. the game ran well with all physx effects enabled in advanced mode and the k620 consumed little power. I also noticed an vram improvement because effects occupied the other gpu.
with only the GTX 750 it was impossible to achieve, so in some scenarios it works really well.

 

[sLowEnd]

I remember playing Batman Arkham Asylum with it. That's about it. There were a few other games that had GPU accelerated PhysX, but I never played them, or if I did, I never specifically looked to turn on GPU PhysX. Haven't heard Nvidia mention it in marketing material in a long time, so I guess they don't care about it anymore.

 

[Deleted member 182555]

I think it depends on SDK and how it was implemented, if PhysX3Gpu_x64.dll is missing it will only be cpu. some effects are gpu only.
latest sdk removes support for maxwell probably because they use a more recent cuda version.

try setting CUDA on the second gpu.

 

[80251]

Unfortunately for me trying to squeeze a second GPU into my rig w/the massive 4090 is impossible, otherwise I would've tested dedicated PhysX w/the 1080ti. Although it might be doable if I remove the fans from the heatsink (because from what I've seen a dedicated PhysX GPU doesn't use much power).

 

[zoulztealer]

got a strange reply from nvidia on this:

The Physx system software is no longer included in the NVIDIA Game Ready Drivers. You will need to download and install it separately in order to use the GPU Physx when a game/application doesn't include all of the Physx library files. Once installed, please make sure you have also enabled a Physx feature so that it shows up correctly in the overlay.

NVIDIA PhysX System Software

NVIDIA PhysX System Software

www.nvidia.com

Unfortunately for me trying to squeeze a second GPU into my rig w/the massive 4090 is impossible, otherwise I would've tested dedicated PhysX w/the 1080ti. Although it might be doable if I remove the fans from the heatsink (because from what I've seen a dedicated PhysX GPU doesn't use much power).

i believe dedicated physx gpu on a seperate gpu may even cause worse performance than running it from cpu or from the actual gpu - as youve showed before with your benches.