I have this game in ISO format on my Memory Stick PRO Duo. I have Pro CFW 6.60 on my PSP and I used it to set the clock speed to 333/166 for games and XMB and set UMD ISO Mode to M33 Driver. There is no option for ISO Video Mount.
The game usually runs OK, but if I drive around with a 3-star or higher wanted level, the frame rate is noticeably affected and sometimes I get severe lag spikes.
I also have Liberty City Stories, which runs better, but not perfectly. At all times, its frame rate is better than that of VCS, but it does drop when driving with a wanted level. However, in LCS I don't experience tremendous lag spikes, like in VCS.
BTW, I also have NFS Most Wanted 5-1-0, which runs flawlessly all the time. So it's not a problem with the PSP itself.
Is there any way to make Vice City Stories run better?