2.8ghz Pentium 4, 1.5gb RAM

Been told the reason it slows down is when transferring large-ish files from one HDD to the other, as IDE cables can only access one drive at a time, so it sends the info down the cable from the primary drive, reads the info, then sends it back up the cable to the slave drive, then repeats the steps - but it's READ > WRITE > READ > WRITE > READ > WRITE etc, never reading and writing at the same time..... Due to the layout of the devices on the cable arrangement.....