I'm guessing quite a large chunk of that "~900 MB" is actually a swap file? ICEł will definitely slow down once it creates a swap file.
Hmm, I went to go check that for you, and now it won't start. I clicked it and it's just bouncing in the dock, with CPU usage at 90%, VM memory usage for the thread at 3.85 GB, Real Memory usage at ~900 MB. And it wouldn't start.
10000 tracks with a PowerPC? Are there any other PowerPC users with a library of this size?
All I changed was the fact that I added about 10000 Mp3's. This simply might be too much for the PowerPC processor to handle. I may have to rethink my CarPC plans, or just upgrade to an Intel Mac Mini.