Hello community, thanks for reading this post. I have a really good gaming computer (16GB RAM, quad core 3.8 ghz, AMD HD 7950, new motherboard etc.) and I have no problem running absolutely any game on the highest graphical settings. I recently installed The Wither 2 and I have experienced some weird lag. Even though the cpu and the ram never exceed 50%, whenever the game switches between a dialogue to gameplay or to a cinematic and vice versa, it lags for the first 5 to 10 seconds. Its like my hard drive can't read the information fast enough. My hypothesis is that since the cpu is not working much, the games doesn't load long enough to give enough time for the hard drive to read all the textures etc. The hard drive is the only old and pretty average thing in my computer (1 tb). Thank you!
Witcher 2 is a very GPU heavy game. I suspect that there is not enough VRAM on your 7950 or the game is not optimized to preload textures before displaying/returning from dialogue/cinematic. When a significant amount of new textures has to be loaded rapidly your HDD read rate is bottlenecking the GPU, causing frame skipping. Other thing is the ubersampling which can kill the framerate. Turn it off and see if that helps.