First up, specs:
i5 2500k 4.8Ghz
14gb DDR3 1600mhz
560 ti 1gb (not 448 core) tweaked to use GPU acceleration.
AVI MPEG-1 VBR
I enabled Mercury playback engine, and allocated 11 of my 14gb to premiere. I have also selected clips and have done "preview renders" (makes the bars above the clips green), and not matter what, when I try to preview any clips I get REALLY choppy video, around 1fps, regardless if it is full, half, or quarter resolution. If I check my system stats in resouce monitor, CPU jumps to about 30% (from 10%), ram usage barely moves at all (I have a RAM cache program [not the same as windows built in caching]) and hard drive I/O goes to about 50%. My HDD is also defragmented using the program defraggler.
Mpeg 1 in an avi container? Where does this clip come from.
You probably need to convert.
A screen capture program called bandicam