[clug] USB flash disks

Brad Hards bhards at bigpond.net.au
Wed Jan 28 09:57:56 GMT 2004


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On Wed, 28 Jan 2004 20:48 pm, Eyal Lebedinsky wrote:
> I am testing an external 512MB USB 2.0 flash disk. Measuring xfer time
> I get about 10-11MB/s writig to it (less than USB1.0 for sure) while
> it reads at just under 40MB/s.
USB 1 has a theoretical (absolute, best case, never-going-to-happen) 
performance of the order 980KB/s. 10-11MB/s is order of magnitude better.

> The reading seems to be reasonalbe given the protocol overhead
> (well, raw 480Mb/2 is 60MB/s). However the write is very slow.
You using a 2.4 kernel? I think it is partly the fault of the device, and 
partly the fault of the SCSI layer. 2.6 may be better.

Brad
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