Really? You don't say! The FW interface is faster than USB 2.0? OMFG, I never knew!
I never said anything about USB 2.0 vs FW interface speeds. I said "...between USB and FW800
with this drive". In other words, my pathetic 2.5" hard drive is probably the bottleneck and that I doubt I'd see much of a difference if I put it in a USB enclosure vs a FW800 enclosure.
The drive is a Fujitsu MHZ2120BH, which came with my Mac Mini. It sucks as far as speed goes.
I couldn't find throughput numbers for it, so I ran xbench and got these results (best of 3 runs). This is for the drive installed in the Mac Mini (I had to put the drive back in, after the POS Seagate Momentus died on me, so I don't have USB performance numbers).
Disk Test 47.37
Sequential 61.22
Uncached Write 80.91 49.68 MB/sec [4K blocks]
Uncached Write 73.56 41.62 MB/sec [256K blocks]
Uncached Read 34.82 10.19 MB/sec [4K blocks]
Uncached Read 93.83 47.16 MB/sec [256K blocks]
Random 38.63
Uncached Write 14.75 1.56 MB/sec [4K blocks]
Uncached Write 89.05 28.51 MB/sec [256K blocks]
Uncached Read 67.59 0.48 MB/sec [4K blocks]
Uncached Read 102.77 19.07 MB/sec [256K blocks]
Obviously, speed with be somewhat better with caching, but then again, benchmark speeds are typically better than what you'd see in real life. Sequential read/write goes from 10BM/sec up to 49MB/sec, but I've always felt random read/write is more indicative of real-world usage. That ranges from a blistering 0.48MB/sec to 28MB/sec.
FW800 seems to get real-life speeds up to roughly 55MB/sec, and USB 2.0 seems to get around 30MB/sec. Given these numbers, I'd say for real-world usage, I most likely would not notice a difference.
Of course, it's a moot point since I had to put the drive back into the Mini. Check out Newegg's reviews for the 2.5" 7200rpm Seagate and you'll see a whole slew of people with drive failures. But that's an entirely separate issue.