I installed the trial version of Cineform's 3.3 ConnectHD. I'm working with Sony Vegas 7.0d on a pretty strong computer.

Intel Core 2 Duo E6600
2Gb RAM
SATA-RAID, etc...
Nvidia 7900GT Video Card, etc..

I used the HDLink application to capture and convert to the Cineform .AVI codec. When I do this and load that .AVI file onto my timeline, playback performance on the timeline suffers greatly! While previewing in half resoltuion (good setting) my systme is only able to playback at about 20fps. The irony here is that the raw .m2t HDV file that I load onto the timeline plays at 29.97fps without a hickup, even after a good editing session.

What gives? I expected the intermediary to allow me BETTER performance, not worse.

Am I doing something wrong?!?!?!??

Yes, something must be wrong as my laptop does 29.97 without issue. Note: try "preview" rather than "good" -- Vegas may doing a full-res decode then resizing down -- that would be slow.