graystrickland Posted May 9, 2003 Report Share Posted May 9, 2003 I'm using Retrospect Multiserver 6.0 to do a FILE backup to an exerntal USB drive over a USB 2.0 connection. Retrospect reports speeds for backup in the range of 70 MBpm. 70 MBpm = 1.16 MBps 70 MBpm = 560 Mbpm = 9.33 Mbps USB 2.0 claims speeds up to 480 Mbps 480 Mbps = 28800 Mbpm 480 Mbps = 60 MBps = 3600 MBpm The hard drive in question is an IDE ATA 133 Maxtor 120 drive inside an external enclosure which has an IDE/USB 2.0 (and 1394 Firewire) controller/interface. I'm not sure, but I believe that *all* USB drives are really just IDE drives behind a USB controller/interface. ATA 133 IDE drives can theoretically handle 133 MBps 133 MBps = 7980 MBpm 133 MBps = 1064 Mbps = 63840 Mbpm But since a chain is only as strong as its weakest link, the ATA 133 drive is throtalled down from a max of 7980 MBpm to no better than the USB 2.0's potential speed of 3600 MBpm. Q. - Why is Retrospect running so slow? Granted, I don't expect 3600 MBpm, but why only 70 MBpm? _______ ASSUMPTIONS: MBps = MegaBYTES per second MBpm = MegaBYTES per minute Mbps = MegaBITS per second Mbpm = MegaBITS per minute 1 MB = 8 Mb 1 Mb = 0.125 MB Link to comment Share on other sites More sharing options...
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