[HardOCP] AMD and NVIDIA GPU Vive VR Performance in Raw Data

[Yakk]

But gameworks only applies to certain effects and features in the game that can be disabled, and not the entire source code of the game. Isn't that so?

If that's the case, then NVidia shouldn't be able to prevent the developer from optimizing the non-gameworks code for AMD.

The effects for gameworks are most probably in a specific closed library, but the interaction of the library effect with the rest of the code can most certainly be an issue. Think of it as a problem thread in your code. That one thread can work well on its own, but interfere with the rest the code and cause slowdowns, or even crash the whole program. Nvidia won't care about what doesn't affect them, but won't want AMD to help the devs debug their code for fear AMD could steal said code.

 

[eddman]

The effects for gameworks are most probably in a specific closed library, but the interaction of the library effect with the rest of the code can most certainly be an issue. Think of it as a problem thread in your code. That one thread can work well on its own, but interfere with the rest the code and cause slowdowns, or even crash the whole program. Nvidia won't care about what doesn't affect them, but won't want AMD to help the devs debug their code for fear AMD could steal said code.

Again, do we know for sure that's the case? Why would a developer attach the gameworks code to the main code in such a way that would interfere with it. AFAIK, Nvidia specific effects can be disabled in settings. Are there any games that lack an on/off switch?

 

[Bacon1]

But gameworks only applies to certain effects and features in the game that can be disabled, and not the entire source code of the game. Isn't that so?

Some effects are built into the engine such as Physx and can not be disabled. Same with other features like Waveworks and others which are part of the core game engine.

 

[Stuka87]

Again, do we know for sure that's the case? Why would a developer attach the gameworks code to the main code in such a way that would interfere with it. AFAIK, Nvidia specific effects can be disabled in settings. Are there any games that lack an on/off switch?

Because the game maker receives an undisclosed amount of income/support from nVidia. Its almost never up to the software developers themselves, these are decisions made up top.

And it depends which features are being used. In the case of The Wither 3, HairWorks can be disabled. Although its on by default, so all game benchmarks ran when the game launched caused AMD cards to get crushed. Plus nVidia made it default to 64x tessellation, which looks identical to 16x tessellation in game play, but has a huge performance impact. But the other parts of the Gameworks used in the game are always on, and cannot be turned off.

AMD did eventually find some happy paths for these, and The Witcher 3 now runs quite good on AMD hardware. But launch day benchmarks, which is what everybody looks at, look horrible. So even 6-12 months later, when people look up those benchmarks, they still show the bad AMD performance, not the updated performance.

VRWorks which is used here will end up being more of the same. AMD will be locked out of making optimizations in an easy fashion by working with the developer. So all these early alpha up till release benchmarks will most likely be very skewed.

Some will say AMD does the same, but in no case does AMD prevent a developer from working with nVidia. An example here is AotS, which is sponsored by AMD, but the dev team still works with nVidia for optimizations.

 

[eddman]

Some effects are built into the engine such as Physx and can not be disabled. Same with other features like Waveworks and others which are part of the core game engine.

Hmm, PhysX in witcher 3 is not GPU accelerated. It's only CPU based, meaning it shouldn't matter what kind of GPU you have.
Does it even have waveworks? Last time I checked it only had fur and hair which can be disabled.

But the other parts of the Gameworks used in the game are always on, and cannot be turned off.

AMD did eventually find some happy paths for these, and The Witcher 3 now runs quite good on AMD hardware.

Which other parts? AFAIK, it had fur/hair and PhysX (CPU). What other effects are there?

Maybe there was some other reason for the bad performance on AMD cards? Is there any concrete information anywhere about all this, or is it just something that originated from theories on internet forums?

 

[Bacon1]

Hmm, PhysX in witcher 3 is not GPU accelerated. It's only CPU based, meaning it shouldn't matter what kind of GPU you have.
Does it even have waveworks? Last time I checked it only had fur and hair which can be disabled.



Which other parts? AFAIK, it had fur/hair and PhysX (CPU). What other effects are there?

Maybe there was some other reason for the bad performance on AMD cards? Is there any concrete information anywhere about all this, or is it just something that originated from theories on internet forums?

I wasn't talking about Witcher 3, but it used Physx for cloth and destruction as well as Hairworks, not sure if you can disable the cloth / destruction or not as well.

But other games like War Thunder or Just Cause 3 have settings that you can't disable, not to mention physx itself in many games and UE4 itself to get back on topic.

 

[eddman]

I wasn't talking about Witcher 3, but it used Physx for cloth and destruction as well as Hairworks, not sure if you can disable the cloth / destruction or not as well.

But other games like War Thunder or Just Cause 3 have settings that you can't disable, not to mention physx itself in many games and UE4 itself to get back on topic.

Witcher 3 was supposed to come with GPU PhysX, but that didn't happen. It's CPU only, so no effect on the video card, at all.

Do not confuse CPU PhysX with GPU PhysX.

War Thunder and Just Cause 3; what settings, to be exact? The majority of PhysX games are CPU only, and the PhysX in UE is CPU only by default.

EDIT: Just doing some research. War thunder comes with two gameworks effects. The first is destruction which is CPU only here. The other is waveworks but as far as I can tell, it's CPU only here too.

EDIT 2: Just cause 3 comes with waveworks buts it's CPU only too. No effect on GPUs.

 

[shabby]

How can anybody give an honest suggestion for what card to get based on a sample set of 1?

Hah that's gold jerry, gold!

 

[bystander36]

Some effects are built into the engine such as Physx and can not be disabled. Same with other features like Waveworks and others which are part of the core game engine.

Any PhysX built into the engine that cannot be turned off, is not GPU accelerated PhysX and is performed by the CPU.

 

[Bacon1]

Witcher 3 was supposed to come with GPU PhysX, but that didn't happen. It's CPU only, so no effect on the video card, at all.

Do not confuse CPU PhysX with GPU PhysX.

War Thunder and Just Cause 3; what settings, to be exact? The majority of PhysX games are CPU only, and the PhysX in UE is CPU only by default.

EDIT: Just doing some research. War thunder comes with two gameworks effects. The first is destruction which is CPU only here. The other is waveworks but as far as I can tell, it's CPU only here too.

EDIT 2: Just cause 3 comes with waveworks buts it's CPU only too. No effect on GPUs.

Yes and they hurt AMD cards more because they are already relying on the CPU more for DX11. So when you are forcing the CPU to do more work... they run slower than they would otherwise.

 

[eddman]

Yes and they hurt AMD cards more because they are already relying on the CPU more for DX11. So when you are forcing the CPU to do more work... they run slower than they would otherwise.

So it's not NVidia's doing then. Even if game developers went with Havok, it would've still affected the CPU.

 

[Yakk]

With all the NDAs in place, finding a "smoking gun" argument is pointless. I don't even know how CD Projekt got away with saying as much as they did.

Anyhow, AMD did address this with DX12 & Vulkan through creating Mantle. It becomes very visible with a profiler and whatnot identifying what is happening within the game when using the correct or incorrect codepath.

Case in point, Raja himself tweeted about this VR review :

https://mobile.twitter.com/GFXChipTweeter/status/760303615516880896

Raja Koduri
Raja Koduri – ‏@GFXChipTweeter

@hardocp we are looking into it. Suspect an older version of ue4 in this title prior to our vr optimization work.

Raja Koduri
Raja Koduri – ‏@GFXChipTweeter

@hardocp we are looking into it. Doesn't align with the performance we are seeing with recent builds of ue4 engine.
7:43 PM - 1 Aug 2016 from Saratoga, CA

Similar situation happened with Gears of War when nvidia's gameworks features broke the game completely for AMD. They were quickly able to identify what was going on.

 

[Bacon1]

So it's not NVidia's doing then. Even if game developers went with Havok, it would've still affected the CPU.

Except Nvidia is the one writing the code and not Havok.

 

[eddman]

With all the NDAs in place, finding a "smoking gun" argument is pointless. I don't even know how CD Projekt got away with saying as much as they did.

Anyhow, AMD did address this with DX12 & Vulkan through creating Mantle. It becomes very visible with a profiler and whatnot identifying what is happening within the game when using the correct or incorrect codepath.

Case in point, Raja himself tweeted about this VR review :

https://mobile.twitter.com/GFXChipTweeter/status/760303615516880896



Similar situation happened with Gears of War when nvidia's gameworks features broke the game completely for AMD. They were quickly able to identify what was going on.

EDIT: I just read what CDproject said back then. Everything that they said was public knowledge already. Hairworks is a GPU accelerated effect and it doesn't work well on AMD cards, BUT it can be turned OFF. Do that and the problem is gone.
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That doesn't prove NVidia is actively blocking the developer from optimizing the non-NVidia code for AMD cards.

How are we sure it's the gameworks, which is CPU based to begin with, that's breaking the game for AMD cards? It's quite possible that it was something else in some other part of game's code. Even if it was the case, which looks more and more unlikely at this point, how do we know NVidia intentionally introduced that code, just to break AMD cards?

In those tweets, Raja is just saying that it could be because of the old UE build. That could mean many things. There is no way to tell which part of the UE was causing issues. It might very well be the code written by Epic.

EDIT: Ok, gears of war used HBAO+ for AO, and no other mode was included. It's been known for a long time that it's an NVidia feature that doesn't play well with AMD, and yet MS did not bother to include an AMD friendly AO or at least label it properly or even work with AMD before showing the game, but all this is on MS.

Another issue was that MS didn't even bother with putting an on/off switch for PhysX, which was apparently GPU based. Again, that's the developer's fault for not implementing the switch, or they should've disabled GPU PhysX if they were not going to put a switch for it.

Except Nvidia is the one writing the code and not Havok.

How can an entirely CPU based code mess with the GPU directly? Doesn't matter who wrote it, unless you're saying they purposefully inject bad code to mess with AMD.

EDIT 2: Huh, never knew this. The entire gameworks package, except for waveworks, has been on github for a while. Waveworks is incoming. Now AMD and any developer can change and optimize the code as they see fit. It seems NVidia isn't completely against openness either.

http://benchmarkreviews.com/36129/nvidia-hbao-source-code-now-github/

 

[Cookie Monster]

Yes and they hurt AMD cards more because they are already relying on the CPU more for DX11. So when you are forcing the CPU to do more work... they run slower than they would otherwise.

But isn't that AMDs own short falls? How is that nVIDIA gimping AMD when the fundamental problem here is that AMD has a large CPU overhead in DX11 compared to nVIDIA?

 

[Mikeduffy]

Have you guys even seen this game? It looks like complete garbage.

Who cares about an early access game that literally zero people will play?

PlayStation VR is where we'll see the real games and I doubt AMD will have any issues running these titles.

Kyle is claiming that this is a very influential title - what a load of crap.

 

[Cookie Monster]

Have you guys even seen this game? It looks like complete garbage.

Who cares about an early access game that literally zero people will play?

PlayStation VR is where we'll see the real games and I doubt AMD will have any issues running these titles.

Kyle is claiming that this is a very influential title - what a load of crap.

Well the very same thing has been said for Ashes of Singularity on the DX12 front.

 

[pj-]

Have you guys even seen this game? It looks like complete garbage.

Who cares about an early access game that literally zero people will play?

PlayStation VR is where we'll see the real games and I doubt AMD will have any issues running these titles.

Kyle is claiming that this is a very influential title - what a load of crap.

Guessing you don't really follow VR.

Raw Data doesn't look like much (most VR games don't), but it was one of the most anticipated titles to come out after the initial launch period. It was one of the most covered VR titles at e3/gdc this year and it is also one of the most graphically advanced. A consistent 90fps with a nearly 4k sized frame buffer is going to be demanding on any GPU.

The vast majority of crossplatform PSVR games will be PC to PS4 ports. Stuff developed from the ground up for PSVR is likely to be Sony funded and wouldn't go to the PC anyway.

 

[exar333]

Have you guys even seen this game? It looks like complete garbage.

Who cares about an early access game that literally zero people will play?

PlayStation VR is where we'll see the real games and I doubt AMD will have any issues running these titles.

Kyle is claiming that this is a very influential title - what a load of crap.

Lol. You are kidding, right? PSVR will be a joke, even with the PS4K. Lower powered, fake 120hz (60hz with interpolation) and lower res displays. Like others said, lots of ports and gimmicky stuff. Likely will get better, but graphics wise it will be very limited.

 

[Krteq]

EDIT 2: Huh, never knew this. The entire gameworks package, except for waveworks, has been on github for a while. Waveworks is incoming. Now AMD and any developer can change and optimize the code as they see fit. It seems NVidia isn't completely against openness either.

http://benchmarkreviews.com/36129/nvidia-hbao-source-code-now-github/

Incorrect. It is on github, but it's available for registered developers only and it's still under nV license (not GNU or MIT), so it's still closed source

 

[antihelten]

EDIT: I just read what CDproject said back then. Everything that they said was public knowledge already. Hairworks is a GPU accelerated effect and it doesn't work well on AMD cards, BUT it can be turned OFF. Do that and the problem is gone.
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That doesn't prove NVidia is actively blocking the developer from optimizing the non-NVidia code for AMD cards.

Eerm, CD Projekt Red directly stated that they cannot optimize for AMD, how in the world does than not prove that Nvidia blocked them from doing so?

 

[96Firebird]

Eerm, CD Projekt Red directly stated that they cannot optimize for AMD, how in the world does than not prove that Nvidia blocked them from doing so?

Re-read the last sentence you quoted, then re-read the article you linked.

 

[antihelten]

Re-read the last sentence you quoted, then re-read the article you linked.

"the code of this feature (Hairworks) cannot be optimized for AMD products"

CD projekt RED has access to the source code and yet cannot optimize for AMD, how can that possibly be unless Nvidia are blocking them from doing so?

Please enlighten me.

Edit: I see now that Eddman was going off on a complete non-sequitor about "non-Nvidia code". I hope you can forgive me for making the above mistake given that no one had said anything about Nvidia blocking non-Nvidia code up until his post, but was rather talking about Nvidia blocking optimization of Nvidia code.

 

[96Firebird]

Edit: I see now that Eddman was going off on a complete non-sequitor about "non-Nvidia code". I hope you can see forgive me for making the above mistake given that no one had said anything about Nvidia blocking non-Nvidia code up until his post, but was rather talking about Nvidia blocking optimization of Nvidia code.

You have been forgiven.

 

[antihelten]

You have been forgiven.

Much obliged.