Compressor: Only 60% CPU

FCP is rendering and managing the GOP sequences in order to correctly place compression markers at edit points and sequence boundaries. To speed things up you may want to export your timeline as a QuickTime movie using current settings. Then, when this export is finished import the resultant movie into Compressor, select your preset, and submit the job for batch processing. If you select to export as a reference movie ( not self-contained) the export should run pretty quickly and the resultant movie file should be fairly small (assuming that all of your rendering is already done).

It also seems that Compressor 2 and Final Cut Pro v5 are slower than their earlier versions -- at least they are when doing exports from FCP to Compressor.

Yes, by timeline I meant the main FCP sequence.

When you export as a QuickTime Movie using Current Settings (option "Setting: Current Settings") you're just writing out a copy of the existing FCP sequence. If you're editing in DV there will be no quality loss when you export (in comparison to the DV sequences as they exist in FCP -- since you're just rewriting the files in DV not transcoding to another format). In fact, if you export as a reference movie you'll just be using pointers to the same files that FCP uses to generate your final movie.

As far as image quality I suspect that you'll see little difference between direct exports from FCP to Compressor as opposed to exporting as a QuickTime Movie and then taking that exported movie and submitting it to Compressor. Don't confuse the above method with Export Using QuickTime Conversion -- that's a different process. You can check the manual or the FCP help files to learn more about the differences and options

The one advantage that the direct export from FCP to Compressor has is that FCP will insert reference frames at each edit point in your movie (if possible, since reference frames or i frames must occur on Group Of Picture boundaries). In theory that will improve the quality of the movie since edit points usually occur at scene transitions or filter points and that's where the MPEG compressor usually has to work the hardest to retain quality. Think of a series of still pictures, you'll want a reference frame at the start of each picture and FCP will do that for you automatically.

If you haven't completely rendered your timeline sequence when you perform an export as a QuickTime Movie FCP still has to render anything that is yet undone. That can take time. What is the format of your source video and what are your current sequence settings? If they don't match when you export using Current Settings the entire timeline sequence will have to be rendered and/or recompressed. However, this is not a shortcoming of the Current Settings export method, it's just doing what you're telling it to do. In any case, whenever possible your sequence settings should match the format of your source video (if they don't match your project will have to undergo a possibly unnecessary conversion step when your timeline sequence is rendered).

However, if there is no rendering to be done and the source video is in the same format as your current sequence setting there will be no recompression of the timeline sequence when you export using "Current Settings" (it will just copy the existing timeline sequence). In fact, as I said before, if you export as a QuickTime Movie and de-select (checkbox) the "Make Movie Self-Contained" option you will export a so-called reference movie that just contains pointers to your original clips (if in the same format as your sequence) and copies of any rendered/effects segments. This will typically result in a faster export and a much smaller export file without any loss in quality from you rendered timeline sequence.