So I recently ordered a 5770 from HIS, and my computer did not seem to like it very much. I returned it and got a 5770 from powercolor, and I have some similar issues to what the HIS one had as well. I have had an issue where my computer would look like it restarts itself a few times before it turns on, but I just figured the first 5770 was maybe defective. I still have this problem with this card, but most everything else seems at least OK.
So my main issue is with fullscreen gaming resolutions. Whenever I try to run a game in full screen (I have tried borderlands and Team fortress 2), my screen is not centered unless it is in the absolute minimum resolution for a game. It looks like the display is shifted to the left by quite a bit, and it is obviously unplayable. Windowed modes are not a problem, but I would prefer full screen (plus it didnt look like borderlands had windowed mode at all). I have not tried other games with fullscreen, but I imagine they would have the same problem as these two games.
Some additional informatin, I upgraded from an 8800GT, which ran fine (also consumes more power then a 5770, so I figure this is not a PSU issue)
Also dirk is probably right, download and install driver sweeper. Delete all Nvidia drivers from your control panal, then remove them with driver sweeper. Then run driver sweeper again in safe mode. It might even be smart at this point to remove your ATI ones as well.
Once you get all of them removed, download and install the newest ATI/AMD drivers from their website.
Alright I will try to fool around with the drivers at some point this weekend. I use a Vizio TV as my monitor currently, connected through a VGA. For some reason, it does like the graphics card being connected through HDMI.
Ill post again over the weekend to see if being thorough with driverse helps this, thanks for your suggestions.