There's been an ongoing controversy that started with the release of Project CARS and has continued on with The Witcher 3: Wild Hunt. What is the controversy? Well, Nvidia's GameWorks is claimed by gamers and AMD to have been designed to cripple performance and sabotage hardware throughput for anything that isn't an Nvidia card.
Ars Technica has a very long and detailed article with a back and forth between both AMD and Nvidia over the GPU fallout, as it borderlines on getting a GPU-gate hashtag and turning everyone into raving rageholics.
After various Reddit threads with thousands of people expressing anger and frustration over the performance of AMD cards running The Witcher 3 and Project CARS emerged, both AMD and Nvidia responded to the consumer outrage. Nvidia claims that this is a hardware issue and not a software issue; this is purely on AMD's end for not providing hardware up to par to handle the tessellation attached to HairWorks, an API under the GameWorks label. The software requires a lot of beefy GPU power, as evidence in some benchmarks where Hardwareluxx found that having HairWorks enabled in The Witcher 3 – improving hair physics and tessellation for characters – caused the frame-rates for the GTX 980 to drop from 87.4fps down to 62.2fps. The real startling piece of data was from the AMD side of the table where the R9 290X went from 75.8fps down to 29.4fps once HairWorks was turned on, proving the claims true that AMD's hardware is crippled drastically once Nvidia's software feature is turned on.
AMD believes Nvidia did this purposefully and debunked claims that they weren't working with CD Projekt throughout development on The Witcher 3 to get maximum performance out of the game. The 75.8fps benchmarks for the R9 290X does at least prove they were working with CD Projekt Red enough to gain satisfactory optimization out of the game – but AMD's chief gaming scientist Richard Huddy explained even further, saying...
We've been working with CD Projeckt Red from the beginning. We've been giving them detailed feedback all the way through. Around two months before release, or thereabouts, the GameWorks code arrived with HairWorks, and it completely sabotaged our performance as far as we're concerned. We were running well before that...it's wrecked our performance, almost as if it was put in to achieve that goal.
Nvidia has been vehemently denying these charges, claiming that they just have engineers working very closely with developers to achieve optimal performance. However, the issue comes in with the fact that the source code for GameWorks is not something developers can share since it's provided under license, as mentioned by GameWork's marketing representative Brian Burke in an interview with PC Perspective...
GameWorks improves the visual quality of games running on GeForce for our customers. It does not impair performance on competing hardware. 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. Most of the time we optimize games based on binary builds, not source code... I believe it is a resource issue.
The issue definitely puts AMD in a tough spot, because they still have to find a way to fix a problem created by software they didn't create.
Nevertheless, WCCF Tech is reporting that AMD is working on and offering some fixes for the HairWorks issue in The Witcher 3, which may help quell some of the unrest in the community.