The current v2.00 Release Candidate (v1.99.11) will never expire, but will insert a WaterMark on your video output.
Sometimes soon, they will release an other build that will let you run it in DEMO in full mode for 1 week. It should be much faster, since there will be no watermark (for 1 week).
I have a Pentium 4 @ 3.2 Ghz and I do about 53 fps (x1.70) if I recall.
What is your CPU and Memory specs ?
CPU speed may also be a factor !
My 2 cents...