here is an alternative that helped me eliminate lagg and crashing in DFC
O&O CleverCache
they let you try the full version for 30 days
though I recommend setting your own profilem theirs is good... but with mine I have a 45FPS instead of the normal 29FPS in DFC
~edit~
also player population plays a good deal into your lagg, late at night when freeport is deserted the lagg isn't so bad