Hi-Speed USB Transfer Speeds seem slow

[smitbret]

I have been trying to to hook up a DVD-RW to my computer via an external enclosure, but I haven't been getting Read/Write speeds that I think I should. I finally broke down and bought a Firewire external enclosure and speeds are fine. The enclosure also has a firewire port so I have run off of that, too, but I get the same USB speeds that way as well.

Ok, here's the details. I started with a cheapy AMC USB 2.0 enclosure with a Pioneer DVR-110D. Hooked it up via my onboard USB 2.0 ports to my Abit AN8-SLI with an AMD Athlon 64 x2 4400+ running Windows XP SP2 and 1gb of memory. The only other USB peripheral was my wireless mouse and keyboard. When burning and ripping DVDs, I would consistently get a max speed of 5.8x. I have since swapped out the motherboard for an Abit AN8 32x, added memory, tried add-on PCI cards, tried the different enclosure, swapped out the DVR-110D for a Lite-On DVD-ROM, Benq 1640, Benq 1650, swapped processors to an AMD 3400+ (single-core) on both motherboards. Still getting a max of 5.8x.

Yesterday I purchased a USB external enclosure for an IDE drive that I am using to back files up (speed isn't that important) and it took more than two hours to transfer 160GB of data from my comp to the external DVD, so it's not the drives, enclosures or cables. But back to the DVD-RW, is my reasoning here correct..... Hi-Speed USB 2.0 has a transfer rate of 480mbps? DVD 1x is 11.08mbps, so I am getting a max of 64.26mbps. Which leaves about 415mbps of theoretical bandwidth available, correct? So why am I capping out 99.9% of the time at 5.8x? Am I missing a setting in the bios or something..... what???? Is anyone out there burning or reading DVDs faster than 5.8x with an external enclosure.
-Brett

[edDV]

I'm getting 18-30MB/s (144-240Mb/s) for hard drive transfer over USB2. This is about half the rate of the same drive on PATA/SATA.

5.8x for DVD writing is about 64Mb/s so you are running less than half hard drive rate. I haven't tried USB2 DVD writing but it seems to be on the slow side.


PS: This on a Core2Duo machine.