Digital Foundry puts The Witcher 3: Wild Hunt's HairWorks feature to the test to determine whether accusations of "sabotage" are founded.

You can view the video analysis below:

The game was tested on a PC running a Core i7 4790K with 8GB of RAM, and benchmarked the same sequence running on a GTX 970 and an R9 290X with HairWorks active and disabled.

The test was run after the 1.0.3 patch which adds several improvements including Nvidia HairWorks performance:

Improves stability in gameplay and the UIImproves performance especially in cutscenes and gameplayFixes grass and foliage popping that could occur after density parameters were changedImproves Nvidia Hairworks performanceBoosted texture anisotropy sampling to 16x on Ultra presetSharpen Post-process settings extended from Off/On to Off/Low/HighBlood particles will now properly appear after killing enemies on the waterCorrects a bug where player was able to shoot bolts at friendly NPCsImproves menu handlingCorrects an issue with Stamina regeneration while sprintingFixes a cursor lock issue that sometimes occurred when scrolling the mapGenerally improves world map focusImproves input responsiveness when using keyboardCorrects some missing translations in the UICorrects an issue in dialogue selectionsRostan Muggs is backMinor SFX improvements

AMD's chief gaming scientist Richard Huddy told Ars Technica:

"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."

GameWorks PR Brian Burke told 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 optimise games based on binary builds, not source code... 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."

CD Projekt RED CD Projekt told Overclock3D:

"Unsatisfactory performance may be experienced, as the code of this feature cannot be optimised for AMD products,"

The developer enabled the use of HairWorks for The Witcher 3 albeit with the following warning:

"Radeon users are encouraged to disable Nvidia HairWorks if the performance is below expectations."

Although Nvidia clarifies the situation with regards to GameWorks running on non-GeForce platforms:

"It's not CD Projekt Red's decision to allow the Nvidia tech to work on AMD GPUs - that is Nvidia's decision and most commonly-used features from us are platform-agnostic. It's the same for CPU-based PhysX and Clothworks as well."

With HairWorks disabled the GTX 970 and the R9 290X offer similar performance, so at least the integration of GameWorks has not crippled AMD GPUs overall.

Digital Foundry concludes:

The bottom line is that if a superb card like the GTX 970 (which is running the optimised HairWorks code, remember) produces sub-30fps performance dips with the technology enabled, that's a lot of GPU resource that could be better spent elsewhere, like aiming for a consistent 60fps for example.

The Witcher 3 Hunter’s Config is a nice little tool offering easy access to graphical options, and it's certainly worth a look.

As we have previously covered a few adjustments in the ini files can improve thegrass quality in The Witcher 3, as well as the performance. Aworkaround on how to run HairWorks on AMD GPUs without crippling performance, has also been made available, enabling AMD GPU users of enjoying The Witcher 3 with HairWorks enabled, while getting better performance than GeForce users not using a Maxwell architecture Nvidia GPU.

A set of beautiful4K screenshots of the PC versionand some4K gameplay footage, demonstrates just how amazing The Witcher 3: Wild Hunt can look.

The Witcher 3 is available for the PlayStation 4, Xbox One and PC. We will bring you any new information on The Witcher 3 as soon as it becomes available. Be sure to check out our previous coverage for more information on The Witcher 3,here and here.