Windows uses external hard drives (both USB and FireWire) different than internal drives. The main difference being that write caching is disabled so that you can safely remove the drive at almost any time.  This is fine for drives that you routinely remove from the computer and carry around, however if you have an external enclosure that you never disconnect from your computer, this same feature dramatically slows down your drive performance.

Here is how to get your lost performance back;

In Windows Vista;

Click on the start button, then right click on Computer and select Manage.

Click on Device Manager on the side menu.

Expand Disk drives and locate your external drive from the list.

Right click on the drive and select Properties.

On the Policies tab, select Optimize for performance.

Next, check Enable write caching on the disk and Enable advanced performance as shown below.

Hit OK and reboot.

In Windows XP;

Right click on My Computer and select Properties.

Click on the Hardware Tab.

Expand Disk drives and locate your external drive from the list.

Right click on the drive and select Properties.

On the Policies tab, select Optimize for performance.

Hit OK and reboot.

Tags | General, Windows Vista, Windows XP