They told me to take it to an Apple Store, but no reservations are available until next week...
460 here, had some very minor artifacts in some videos and images. Got a replacement (for another reason) and haven't noticed it on here. Software or hardware? Seems some units are unaffected so it could be hardware.
But was it active, or system tried to launch it, and failed to do so? Because thats what can cause the glitches.
I have this problem. All the .gpurestart and kernel panic logs in Console point to an interaction between "com.apple.photos.ImageConversionService" and the discrete video card.
My large Photos library is uploading in the background.
The Apple Support person hasn't heard of this problem.