How do ensure my PSP is running at 333 mhz?

I am running 3.52 M33-4. My isos seem to be running slow and keep freezing. Everything else works fine. Thanks everyone.

go to recovery mode and check your CPU speed

you can try backing up the files on your computer and format your memory stick. then put the files back on the psp. And go to the recovery menu and see what speed your psp is going. i am on 3.40 OE and have kept my speed at 222, it all works fine for me.

It depends on the size of your ISO, usually the bigger sized files tend to lag a little. If this applies to you, then i suggest searching for a ripped version of your ISO or even a copy of it in CSO format. You can change your cpu speed by turning off your psp, holding the R trigger when you turn it back on then youll be in recovery mode. Look for cpu speed and change it to 333.