I bought a R9 280X Toxic in November to use in my old PC and to use in a future build (link below) that I ended up completing in early December. In my old PC (AMD 955BE, 8 GB RAM, etc.) I noticed some artifacting and the occasional small black boxes on the screen during games with the card in my old computer. I kind of just wrote it off bad drivers, buggy new games, old computer, etc. After completing my new build I still was experiencing the problems, and since then they've started to get worse.
Most games (WoW, BF4, CoD: Ghosts, ARMA 3) will run and look great with minimal artifacting about 75% of the time. The rest of the time the artifacting will get to the point where the game is unplayable or the game will just freeze and crash. Occasionally, I'll get an error message saying the AMD driver has experienced a error and stopped working. I'll have to force a quit through the task manager. I'm running most of the games on the recommended setting (usually high or ultra) and playing at 1920x1080. I've also noticed some artifacting, although pretty rare, while watching something on youtube. I haven't tried tweaking or overclocking the card, and have been monitoring my temperatures, nothing seems to be out of the ordinary. GPU temps tend to stay around 30 deg C while idle and get up to the 50-65 while playing. CPU temps are fine, and currently running at stock speeds.
I'm pretty sure the problem is a defective card, but I'd like to be certain before sending it back since it's hard to find in stock and the price increase. Here's what I've done so far to try and troubleshoot the problem: I've tried the two most recent Catalyst drivers, neither seems to work well. My device manager isn't showing a problem with any drivers. I've updated the BIOS on my motherboard as well as installing the most recent of all other drivers. I ran the Windows diagnostic for memory this morning, but had to leave for work before it was completed. I'm going to try switching out the cables and ports I'm using on my power supply in case that's the problem. Any other advice on things I need to try out?
Note: Both new and old computer are running Windows 8.1