Does anyone (and this question is addressed to the math experts out there) have a general feeling for the throughput you would see on a disk to disk copy on an empeg?

I haven't timed disk-to-disk, but memory-to-disk gets about 4Mbytes/sec, and it's CPU-bound, so I wouldn't expect more than 2Mbytes/sec disk-to-disk.

This is much less than the head rate of modern laptop disks, so you should be able to do much better if you put them into a Linux PC with an adaptor.

Peter