The third public Beta of Witcher 2 has been released on Steam.
If it will improve the modest performance on Linux has yet to be tested.
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Changes according to https://github.com/KillaW0lf04/The-Witcher-2-Issues

11 Aug 2014 14:34 BST

Public Beta 3 - buildID 352258

This contains the following:

Optimised shader compilation to link OpenGL programs in waves, instead of one by one, which makes it possible to speed it up using threaded shader compilation on some cards.
Drawing of fullscreen quads optimised
Optimized out some memory barrier commands from OpenGL command queue
OpenGL rendering never lags more than one frame behind commands given by D3D, which should reduce mouse lag.
Added better reporting of missing extensions in game log, to make it more visible when the game is slow due to OpenGL not supporting various features.
Undid the regression of fullscreen monitor selection support - this should now work correctly again

Also added is a new sound backend - using openal-soft instead of SDL's audio. We've had better performance out of this with FMOD, so we added it here to see if it improves the sound situation. Note that this now means the "Audio" option in the configuration options no longer functions, and openal-soft will use an .alsoftrc if you have one. If you have any audio problems, and have a custom .alsoftrc, please attach it to any bug reports.

We're still finding out what's going on with the game and AMD cards being a lot slower than it should be.. please bear with us!

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