Wait.. Are you talking about an actual thumb stick? Or one of those removeable usb hard drives?
I would give it a go on a thumb stick. However, not a removable hard drive. Those run typically at only 4200rpm. Thats what my 4gb on does..
But realistically I would give the 6gb hard drive a go. Cant hurt anything. Most new motherboard dont come with IDE though, do they? Im not sure.. But yeah, give the hard drive a go. I mean even if there is no performance boost, it still makes your main drive just that much faster right? And as a test I would try a thumb stick. Although if your talking about a mini harddrve, im going to give you a thumb's down..