The speed is quite good, but the CPU load is too high.
on Upload i get 20-30% load (~10mb/s) (athlon XP 1800) with 512 MB ram
on download around 10-20 % (~8mb/s)
Imo 30-40% is not much with such speeds, assuming you are not running with server optimized cache settings. Disk access causes most of the load on ide - get scsi :-)