usb 2 is faster than firewire 400 but only in theory on Mac
You'd think that USB 2.0, at 480 Mbps, is faster than Firewire 400, at 400 Mbps, wouldn't you? Because 480 is bigger than 400?
But it's just not. 480 theoretical Mbps may be faster than 400 theoretical Mbps, but in the real world, firewire 400 is faster than USB 2.0. And when you compare firewire 800 to USB 2.0, there's just no contest. Look at this link, for just one example: Bare Feats (
http://www.barefeats.com/usb2.html)
It says, in part:
Apple states that the USB 2.0 ports on their Macs support transfer rates up to 480 megaBITS per second (Mbps), which translates to 60 megaBYTES per second (MB/s). The most we saw was 144 megaBITS per second or 18 megaBYTES per second.
Think about it. FireWire 400 is rated at 400 megaBITS per second (50 megaBYTES per second) -- 80 megaBITS slower rating than USB 2.0 -- yet when exact same drive/enclosure is plugged into the FireWire 400 port, it goes almost twice as fast!
You can't blame it on the drive, because, as you can see from the FireWire 800 tests, the drive is capable of transfer rates much higher. Some blame it on Apple's USB 2.0 drivers or the USB 2.0 bridge chips. I can't comment on that.
(thanks to the guy that i copied this off)
anyway the bottom line is... fork out for the best if you need it (like you did for your mac) or if you can handle a little bit slower then get the usb... i wou personal get a fw800 with a small hd than a usb 2 with a larger...