Ok, so i was devastated that my computer couldn't run this, even though it can run Crysis high, so, the performance issue was the biggest thing i had in mind all DAY. I've been searching the internet for fixes, but none have been found. But, i saw the light of day, this person did not find the fix, but it gave me the idea. When you set DX10 off ingame, it's not, even though it says its off in the ingame options menu, its not off. So, to fix this, go to the following place: C:\Documents and Settings\All Users\Documents\STALKER-STCS (by documents, it means Shared Documents) then find the user.ltx file, BACK IT UP FIRST open it up with notepad then search for the area where it contains r1, r2, and r3. Search for the following: r3_dynamic_wet_surfaces r3_msaa r3_volumetric_smoke r2_ssao r3_use_dx10_1 Turn at LEAST (r3_use_dx10_1) off, if you don't you DX10.1, turn off all the directx 10 features too, like wet surfaces, volumetric smoke, etc. ssao and msaa are anti-aliasing, which take up ALOT of FPS, there are other graphical options you can tinker with so you get better FPS, save and then close Load up a game and you should see your FPS skyrocket. BUT WAIT! We are not done yet, if you did the following and STILL getting bits of lag, do this: Start the game, go ingame, then press Ctrl+Alt+Delete, when at the task manager, go to the Processes tab, click Image Name so it appear aplhabetical, go all the way down and see xrEngine.exe, right click it and press "Set Affinity" then, check out ever box except for CPU 0, press ok, then go to Affinity settings again and check in those boxes again, press OK and your FPS should be better (works with quad cores and dual cores) So, in conclusion, the game itself is just optimized BADLY, you gotta fix it yourself, the game is telling your computer that DX10 is on, so its creating ALOT of stress. You can tweak the user.ltx file a bit for more FPS, but remember to backup the file. Please request this to be stickied.