I haven't seen it with memory, but I work with an graphics programmer who swears he's done the same trick with CPU cycles, just insert a busy loop that does nothing for a couple of milliseconds every frame (busy loop, not sleep, so it still appears to the casual observer that your rendering engine is working as hard as it can). Then when the game is getting ready to launch, and the framerate is inevitably dropping, remove the loop.

I don't think he has a loop like that in our current code base. But it's possible.