If you are playing PSP games off a memory stick and your game cutscenes lag, the game is slow or other things are happening, it may be the Umd ISO Mode. In this guide I will show you how to change it and which ones to choose On the XMB, press Select to show the VSH menu You will see a screen that looks like this: Depending on what CFW you use, the screen may look different, but should be the same. Using the d pad, go to UMD ISO MODE Now, using the left or right d pad buttons, you can select the following UMD ISO Modes: -Sony NP9660 - Sony's official ISO Driver -Inferno - Optimized driver that's the best with CSO Formats (it has a block offset cache speedup for the CSO format) -M33 (only on older CFW firmwares) - Don't use this! It's outdated! Only do so if NP9600 and Inferno do not work on the game you want to play. I, am choosing Inferno, because my games are in CSO format. But NP9600 is also a good driver if Inferno does not work for you. After choosing your UMD ISO Mode you can either go the exit button and press X, or press select after choosing and it will close it too. You can also enable memory stick speedup if this did not work for you. If you want me to update this guide to include that, let me know and i will do so.