Hi, I've found the following improvements for better and smoother framerates for ps3 games.
Like set the BD/DVD upscaler set off,HDMI 24fps off, HDMI audio set on bitstream, PS2 upscaler/smoother set off.
Disable system display notify/ mediaserver off / all other automatic setting set to off / internet disable if not multiplaying and other setting etc will all help improve framerates.
I tested all the games with HDMI 720p, and all games runs more smoother, speed and more responsive, I think cell dont have to spend time in the background from those settings before.
Let us know if this also helps the framerates for you too.