Very weird problem. About 3/10 times the discrete GPU on the Retina MBP (Nvidia GT650M) does not engage when I launch a game. The performance for the game drops to as if only the integrated GPU was engaged i.e single digit FPS.
This happens when previously the game would work just fine on the same settings. This also happens under the Windows 7 partition under Boot Camp so I know it is not a software issue.
The first time it happened I was completely flummoxed and simply could not find a solution. Just as a last resort I tried resetting the SMC and it started working fine after that.
Another thing is this problem may be occurring a lot more frequently but I can only get to know when I launch a game and it refuses to work properly. For almost all other tasks there is barely a difference when the Nvidia is working. (Guess that's why they let the 13" retina be with just the integrated chip).
Now this problem is occurring frequently enough to really bug me. I have been using a Mac since 2005 and I haven't had to reset the SMC this much in the last 6 years as I've had to in the last 5 or so months of using this machine.
Should I get it checked at the store, ask for a replacement, or is there a more permanent solution that I'm not getting?
Edit Can a mod please change the 'power-management' tag to SMC?