if you don't have USB 2 ports on your computer (you don't if you're HDD is hooked to the computer in your auto signature) then file xfer will only happen at USB 1 speeds. USB 1 has two speed modes, low speed 1.5Mbps and 12Mbps. Very slow for HDD. You might want to look into getting a USB 2 PCI card from MacWarehouse or someplace.