upgraded a R9 270x to a R9290. Having some issues.

Yesterday I upgraded from a R9 270x to an R9 290. Also installed a new 750W PSU. Things work fine for about A half hour,. Then the screen it's messed up looking. It gets very pixilated. Not just a game, the desktop included. I should mention that my PC seemed to not know the difference between the two cards, which I found kinda odd. They are both R9's, so I didn't worry to much. I'm wondering if I'm having a heat issue, what do you guys think?

i7 3440 (I think), 8 gigs of RAM, 750W PSU

Did you uninstall the R9 270x drivers?

@MonsieurX: the weird thing was that the PC did not even recognize a new card. I hit "scan for hardware change" in the Device Manager, it did not find any. But, I can play Just Cause 3 at 1080p with graphics all set to high and everything else set to max with no problems. As soon as my son turns on Roblox, or even Skype one time, the screen gets all pixilated and funky looking

Just Cause 3 runs at about 60fps-40fps when all on high.

@MonsieurX: yes I did. The drivers seem to be the same. I just put the R9's 270x back in. The PC did not notice a change. All games are working fine now, of course on lower settings though. Bad R9 290 maybe?

@gregbmil: Maybe a defective R9 290.

But maybe you need to do a clean install in the drivers.