The other posts answered your question, but here are some more numbers:
- hdparm on the IDE drive gives a raw read bandwidth slightly above 20MB/s (for the 160GB drive).
- hdparm on an external 200GB USB drive gives a read bandwidth around 9MB/s.
- Copying files from one partition of the IDE drive to another partition of the same drive was performed at around 4MB/s.
- Copying files from the USB drive to the IDE drive barely reached 2,5 MB/s.