Speed Issues - eddywebs/RetroPie-Setup GitHub Wiki

BTW, for most of those cores you should be able to get at or near full speed, with some exceptions:

imame4all: Speed depends on the game. Certain Midway games are known for being really slow, like Mortal Kombat or NBA Jam.
pocketsnes: Some games, especially SuperFX and SA-1 games, will be kinda slow on a stock speed Pi. Some graphic effects in other games can lag specific screens. I overclocked/overvolted my Pi to 950 Mhz and it runs most games at full speed, except for the SuperFX and SA-1 ones.
vba-next: Will probably never be fullspeed on the Pi. An alternative port is being considered.
genesis-plus-gx: Is still a bit too slow on the Pi. An alternative port is being considered.
mupen64plus: Due to limited processing power some games will never be fullspeed on the Pi2.
reicast: Due to limited processing power some games will never be fullspeed on the Pi2.
ppsspp: Due to limited processing power some games will never be fullspeed on the Pi2.

General Improvement in retroach

set video_threaded = true in retroarch.cfg will improve video performance

Overclocking Thread of the Official RPi Forum

There is a thread about overclocking the RPi in the official forum of the foundation. You can find it here.

Overclocking With RetroPie Setup

In the menu "Setup" you can find the options for changing the ARM and SDRAM frequencies. Note that changes will take effect after a reboot of the Raspberry.

Overclocking With raspi-config

You can overclock your Raspberry without voiding its warranty with the official raspi-config script. It can be started with

sudo raspi-config

User Comments

From ChadP:

Im running my pi at over_voltage=6. arm_freq=1000. core_freq=500. sdram_freq=500. and the games are fast no lag.

I think that these are options for a heavily overclocked RPi and I would suggest to use a heat sink (at least!)