I have my Retropie running op my Pi 2, and as far as I know, everything is pretty well set.
My issue is that I’m running a lot of games in “demo-mode” and after an hour or two, it happens that the Pi is freezing, or is rebooting ES once, and can also get into an endless loop with a message like “emulation station will reboot after 5 seconds” (reboots and comes back to the very same message).
It happens with PC-Engine, Snes and PSX games, so it’s not emulator-related imo. The memory-split setup is 384mb GPU memory.
Firmware is up-to-date, everything else too.
I did a complete clean reinstall, but that didn’t help.