Subject: Graphics Cards | May 17, 2015 - 12:04 PM | Ryan Shrout
Tagged: The Witcher 3, nvidia, hairworks, gameworks, amd
I feel like every few months I get to write more stories focusing on the exact same subject. It's almost as if nothing in the enthusiast market is happening and thus the cycle continues, taking all of us with it on a wild ride of arguments and valuable debates. Late last week I started hearing from some of my Twitter followers that there were concerns surrounding the upcoming release of The Witcher 3: Wild Hunt. Then I found a link to this news post over at Overclock3d.net that put some of the information in perspective.
Essentially, The Witcher 3 uses parts of NVIDIA's GameWorks development tools and APIs, software written by NVIDIA to help game developers take advantage of new technologies and to quickly and easily implement them into games. The problem of course is that GameWorks is written and developed by NVIDIA. That means that optimizations for AMD Radeon hardware are difficult or impossible, depending on who you want to believe. Clearly it doesn't benefit NVIDIA to optimize its software for AMD GPUs financially, though many in the community would like NVIDIA to give a better effort - for the good of said community.
Specifically in regards to The Witcher 3, the game implements NVIDIA HairWorks technology to add realism on many of the creatures of the game world. (Actually, the game includes HairWorks, HBAO+, PhysX, Destruction and Clothing but our current discussion focuses on HairWorks.) All of the marketing and video surrounding The Witcher 3 has been awesome and the realistic animal fur simulation has definitely been a part of it. However, it appears that AMD Radeon GPU users are concerned that performance with HairWorks enabled will suffer.
An example of The Witcher 3: Wild Hunt with HairWorks
One of the game's developers has been quoted as such:
Many of you have asked us if AMD Radeon GPUs would be able to run NVIDIA’s HairWorks technology – the answer is yes! However, unsatisfactory performance may be experienced as the code of this feature cannot be optimized for AMD products. Radeon users are encouraged to disable NVIDIA HairWorks if the performance is below expectations.
There are at least several interpretations of this statement floating around the web. First, and most enflaming, is that NVIDIA is not allowing CD Project Red to optimize it by not offering source code. Another is that CD Project is choosing to not optimize for AMD hardware due to time considerations. The last is that it simply isn't possible to optimize it because of hardware limitations of HairWorks.
I went to NVIDIA with these complaints about HairWorks and Brian Burke gave me this response:
We are not asking game developers do anything unethical.
GameWorks improves the visual quality of games running on GeForce for our customers. It does not impair performance on competing hardware.
Demanding source code access to all our cool technology is an attempt to deflect their performance issues. Giving away your IP, your source code, is uncommon for anyone in the industry, including middleware providers and game developers. Most of the time we optimize games based on binary builds, not source code.
GameWorks licenses follow standard industry practice. GameWorks source code is provided to developers that request it under license, but they can’t redistribute our source code to anyone who does not have a license.
The bottom line is AMD’s tessellation performance is not very good and there is not a lot NVIDIA can/should do about it. Using DX11 tessellation has sound technical reasoning behind it, it helps to keep the GPU memory footprint small so multiple characters can use hair and fur at the same time.
I believe it is a resource issue. NVIDIA spent a lot of artist and engineering resources to help make Witcher 3 better. I would assume that AMD could have done the same thing because our agreements with developers don’t prevent them from working with other IHVs. (See also, Project Cars)
I think gamers want better hair, better fur, better lighting, better shadows and better effects in their games. GameWorks gives them that.
Interesting comments for sure. The essential take away from this is that HairWorks depends heavily on tessellation performance and we have known since the GTX 680 was released that NVIDIA's architecture performs better than AMD's GCN for tessellation - often by a significant amount. NVIDIA developed its middleware to utilize the strength of its own GPU technology and while it's clear that some disagree, not to negatively impact AMD. Did NVIDIA know that would be the case when it was developing the software? Of course it did. Should it have done something to help AMD GPUs more gracefully fall back? Maybe.
Next, I asked Burke directly if claims that NVIDIA was preventing AMD or the game developer from optimizing HairWorks for other GPUs and platforms were true? I was told that both AMD and CD Project had the ability to tune the game, but in different ways. The developer could change the tessellation density based on the specific GPU detected (lower for a Radeon GPU with less tessellation capability, for example) but that would require dedicated engineering from either CD Project or AMD to do. AMD, without access to the source code, should be able to make changes in the driver at the binary level, similar to how most other driver optimizations are built. Burke states that in these instances NVIDIA often sends engineers to work with game developers and that AMD "could have done the same had it chosen to." And again, NVIDIA reiterated that in no way do its agreements with game developers prohibit optimization for AMD GPUs.
It would also be possible for AMD to have pushed for the implementation of TressFX in addition to HairWorks; a similar scenario played out in Grand Theft Auto V where several vendor-specific technologies were included from both NVIDIA and AMD, customized through in-game settings.
NVIDIA has never been accused of being altruistic; it doesn't often create things and then share it with open arms to the rest of the hardware community. But it has to be understood that game developers know this as well - they are not oblivious. CD Project knew that HairWorks performance on AMD would be poor but decided to implement the technology into The Witcher 3 anyway. They were willing to sacrifice performance penalties for some users to improve the experience of others. You can argue that is not the best choice, but at the very least The Witcher 3 will let you disable the HairWorks feature completely, removing it from the performance debate all together.
In a perfect world for consumers, NVIDIA and AMD would walk hand-in-hand through the fields and develop hardware and software in tandem, making sure all users get the best possible experience with all games. But that style of work is only helpful (from a business perspective) for the organization attempting to gain market share, not the one with the lead. NVIDIA doesn't have to do it and chooses to not. If you don't want to support that style, vote with your wallet.
Another similar controversy surrounded the recent release of Project Cars. AMD GPU performance was significantly lower than comparable NVIDIA GPUs, even though this game does not implement any GameWorks technologies. In that case, the game's developer directly blamed AMD's drivers, saying that it was a lack of reaching out from AMD that caused the issues. AMD has since recanted its stance that the performance delta was "deliberate" and says a pending driver update will address gamers performance issues.
All arguing aside, this game looks amazing. Can we all agree on that?
The only conclusion I can come to from all of this is that if you don't like what NVIDIA is doing, that's your right - and you aren't necessarily wrong. There will be plenty of readers that see the comments made by NVIDIA above and continue to believe that they are being at best disingenuous and at worst, are straight up lying. As I mentioned above in my own comments NVIDIA is still a for-profit company that is responsible to shareholders for profit and growth. And in today's world that sometimes means working against other companies than with them, resulting in impressive new technologies for its customers and push back from competitor's customers. It's not fun, but that's how it works today.
Fans of AMD will point to G-Sync, GameWorks, CUDA, PhysX, FCAT and even SLI as indications of NVIDIA's negative impact on open PC gaming. I would argue that more users would look at that list and see improvements to PC gaming, progress that helps make gaming on a computer so much better than gaming on a console. The truth likely rests somewhere in the middle; there will always be those individuals that immediately side with one company or the other. But it's the much larger group in the middle, that shows no corporate allegiance and instead just wants to have as much fun as possible with gaming, that will impact NVIDIA and AMD the most.
So, since I know it will happen anyway, use the comments page below to vent your opinion. But, for the benefit of us all, try to keep it civil!