I got my PC up and running today, running an XFX R7 250X (or HD 7770 GHz Edition). I installed fglrx (proprietary) AMD drivers on my system, but they didn't work correctly. I then (via system settings) switched to the open-source driver. This worked fine, as I later played TF2 at 80-120 FPS with no issue on highest settings.
However, when I had finished installing CS:GO, I could barely get 15 FPS on the start menu, and when I attempted to load into a Casual match, the PC froze.
I checked my drivers to make sure they were okay, and it said that I was using "custom" drivers. I uninstalled instances of fglrx and the open-source driver, reinstalled the open-source one and deleted all of my games.
I decided to try the ORIGINAL Counter-Strike (the 1999 one), and it installed okay, but it ran in 1024x768, with no option to change it. I thought "oh well, no big deal" until I got into a game. I was putting up 15 FPS, and dropping lower.
What is going on with my GPU? Thanks.