Its SH-4 CPU can be overclocked from 200 to either 220 MHz (which is safer) or 240 MHz (which isn't recommended). Some games which may struggle the original console in heavier scenes (like Soldier of Fortune) or don't run at full speed (like Sega Rally which runs at 55 vblanks/sec instead of 60) will work smoother. Flycast supports overclocking, and Sega Rally runs at full 60 vblanks/sec in Redream.