That doesnt sound to off, about 5mins for me for 100 images. I also use the 50d with raw and that's going usb 2.0 to a firewire hard drive on a mac running on server mode. My CF cards are like 17mb/s cards, 8gb. I also have a 45mb/s 2gb and its alot faster than my 8gbs. No idea what server my school uses.