i tried to export AppleProRes HD to AppleProRes SD with Compressor (1h 35m long material), and for this operation compressor need a 42 hours!!!
Is it normal?
2 x 2.66 DualCore Intel Xeon
6 Gb 667 DDR 2
If you did the operation from the timeline it will take much longer than you'd imagine, especially if there are any unrendered clips. Scaling does after all require encoding every single pixel of every field or frame.
To save loads of time, first export a self contained file as your "master" using Export>>QuickTime Movie, without checking the recompress all frames checkbox. Then use that file in Compressor to create your SD version or any other file type you need.
The initial export from the timeline as I've mentioned above is very fast and makes an exact duplicate of your timeline without losing a generation, and the transcode from that exported file will still take a while, but not even close to 44 hours.