I'm using Ubuntu 9.10 and I have two big external USB HDDs connected to this one computer. I thought I'd copy about 70 GB of data from one to the other. This was a major problem -- it slowed the system to a crawl and it could only move about 100 MB per minute between the drives. It was going to take 12 hours to copy the files. Meanwhile I couldn't use the machine. So I killed the job half way through. Next I tried copying files from one HDD to a supercomputer on our University network. It copied 32.2 GB across the network in 85 minutes, so it was about 4 times as fast as copying from one drive to another on the same machine. Also, it had a minimal effect on my experience as a user while it was moving the files. Then I tried to copy the files from the remote machine back to the other external USB HDD. This was having a big impact on performance, but it was fairly fast -- the files were coming back at the same speed that they had gone out. Thus, this... External HDD #1 --> remote machine --> External HDD #2 ...was about twice as fast as this... External HDD #1 --> External HDD #2 There's something very wrong with a system that works that way. If I had enough space on my internal HDD, I'd do this and probably get even better results: External HDD #1 --> Internal HDD --> External HDD #2 Another crazy thing is that it must have been really killing my CPU because I could hardly do anything else while the drive-to-drive USB transfer was active, but programs like "ps aux" and "top" (both of which literally took minutes to launch) seemed to show that almost nothing was happening. Why is that? Mike