ElDiabloConCaca said:
The fact that IDE and SATA drives "top out" at around 30MB/sec is the limiting factor in the actual speeds of the protocols. 400mbit/sec is roughly 50MB/sec, and, since there isn't an IDE or SATA drive in existance that could possibly sustain that kind of transfer rate (well, there MAY be, but typical IDE/SATA drives do not), you'll likely see maximum speeds closer to 30MB/sec with all of the aforementioned protocols (FW400, FW800, USB 2.0).
This is the very real reality... I was always under the understanding that most drives max out between 35-45 MB/sec. (And that's NOT the sustained transfer rate...) Sure, you can use a faster drive (faster RPM), but even then the results are not significantly faster.
Lets look at the 3 technologies:
(- Remember there's 8 mbit's in 1 MB...)
Firewire800 = 800 mbit/sec = 100 MB/sec
Firewire400 = 400 mbit/sec = 50 MB/sec
USB2.0 = up to 480 mbit/sec = up to 60 MB/sec
(Please correct me if I'm wrong...) But I was told that USB 2 functions at between 12 mbit/sec - 480 mbit/sec, but most of the time (at its best) it works slightly below the 400 mbit/s speed. It is for this reason that video editors preferred Firewire400 over USB 2, because Firewire400 was generally faster. I've just noticed that Apple have removed the Firewire800 port on the new Macbook Pro - which is interesting cos' "Firewire" is an Apple owned technology... Hmmm.
Anyway, my current need for speed is satisfied by an (now unsupported) Adaptec 39160 dual channel SCSI card - each channel operating at 160 MB/sec. My boot drive is a 3rd generation 15,000rpm Maxtor SCSI drive. Even with this beast of a hard drive - the max transfer rate (NOT sustained) is about 90 MB/sec, and sustained output at about 60-65 MB/sec. I also have a RAID setup with two 10,000rpm SCSI drives that achieves a sustained output of 100 MB/sec with large files (the single 15Krpm drive is faster with smaller files...)
So in answer to your question; "What is faster?", well it depends on the setup... If you aren't going to install a RAID setup or a super, fast drive - there will be very little difference between Firewire400 and Firewire800. In fact, there may be little difference between all 3 technologies!
As suggested above, Firewire400 may be "continually" faster, but USB 2 can often be more reliable. If you're getting an external drive enclosure (take the advice that was offered earlier) = get one that supports both!!!