I have AMD A8-3870K APU crossfired with HD6670 and the game played smooth with 12.8 amd driver but when i updated driver to 13.1 it started to lag even in main menu and i would get in game min 15fps max 24fps. This was also problem with AC Revelations but somehow it fixed it self. I have tried to uninstall 13.1 driver and install 12.8 and games work fine but windows explorer and other programs are crashing so I install new driver again and windows is fine but games are not.
P.S. I am know running driver version 13.4 and everything is same.
Hello altutu... sorry to hear about your video problem/issue; I will try to assist. After looking at your Video Card Specs (both are HD 6000 series), the first thing that pops-out at me is Splinter Cell Conviction supports neither one of your video card chipsets. If Splinter Cell Conviction worked before you updated/upgraded your video drivers, then you were just lucky. Splinter Cell Conviction must have (most likely) recognized your video card as a "supported" model (probably the HD 5000 series - not uncommon) and it worked just fine; but as soon as you updated/upgraded your video drivers, now Splinter Cell Conviction does not recognize your video card chipset correctly.... hence the terrible video lag/studder. Having said that, I'm sure if you had Splinter Cell Conviction working fine with the previous video drivers, then it would seem to me that you can "Rollback" the video drivers to the previous version and all should be good. But, in your post you mentioned that when you do this "Rollback" of the video drivers, that your games work OK, but your Windows apps now crash... well, I would suggest (as snoopyau suggested) to do a "Clean-Install" of the previous drivers. What this means is:
1. you need to uninstall all the AMD video drivers completely; either using driver tools or by uninstalling the drivers manually
2. delete any/all folders which contain video driver remnants: search in Windows for any folders/files that contain AMD video remnants
3. clean your Windows Registry (hierarchical database that stores configuration settings and options); CCleaner is one of many registry cleaners available to you as freeware
NOTE: As with all Registry cleaners, I recommend that you proceed with caution before fixing or deleting any files - with this I mean you should backup your registry prior to cleaning; all Windows Registry cleaners should ask you to backup any changes it's about to make and you should definitely do so. You may need to run the Registry cleaner more than once before it comes back with no issues found.
Once you have done this "Cleaning" you should reboot/restart your computer and then proceed to install the AMD 12.8 video drivers that worked for you... this is considered a "Clean-Install". Hope this helps.