Is it dangerous to run a GPU benchmark
I've seen that error a few time on mine since updating to Yosemite. I've taken it in to get checked out and apple didn't find anything when running their tests. One thing I've done to keep it from popping up as much is to do a NVRAM reset. You can do this by restarting before bootup hold command + option P + R till you hear a second startup chime then release. This clears out some video memory and some other minor settings like volume etc.