On Jun 11, 2009, at 3:23 PM, Thomas Charron wrote: > On Thu, Jun 11, 2009 at 3:10 PM, Jarod Wilson<ja...@wilsonet.com> > wrote: >> On Jun 11, 2009, at 1:39 PM, Tom Buskey wrote: >> Typically, no. USB sucks horribly for disk I/O. > > Mostly depends on what your talking about.
Yeah, I left out a "relatively speaking, compared to other external disk interfaces", there. > And the quality of the USB disk/host controller. Eh. Even the best quality stuff gives relatively meager throughput (again, compared with FireWire and eSATA). But its certainly possible to go from bad to worse. >>> USB 2.0 is 480 mbits/s which is probably close to 48 MB/s. >>> 45 MB/s on gigabit ethernet isn't too bad. >> (480 Megabit/second) * (1 Megabyte/8 Megabit) = 60 MB/s. But in >> practice, you'll rarely see much better than about 30MB/s, because >> all >> bus arbitration is done by the host cpu, which is grossly >> inefficient. >> FireWire or (even better) eSATA blows USB out of the water for >> external disk I/O performance. > > True enough. :-D But popping in a USB disk to test it works pretty > well. Don't get me wrong, I do think USB disks are often quite useful. Just, I'd rather use a better interface if I care about performance. My external drives w/USB connections (save USB flash disks) are all USB/ FireWire or USB/eSATA (or even USB/FireWire/eSATA), and USB is only used when the other routes aren't available. That reminds me, I need to pick up an eSATA expresscard one of these days.. -- Jarod Wilson ja...@wilsonet.com _______________________________________________ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/