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Re: How long will this take?

deloptes wrote: 
> Dan Ritter wrote:
> > USB2 disks are good for about 25MB/s.
> > 
> Where do you have those numbers?
> USB 2.0 standard can theoretically transfer data at a very high 480 megabits
> per second (mbps), or 60 megabytes per second (MBps) [for example in
> wikipedia).

Yes, that's the theory. In years of running several USB 2.0
attached disks, I found that they were actually good for about
25MB/s long-term. Bursts to 37MB/s were not uncommon.

The USB mass storage protocol forces a queue depth of 1: one
request, one response, nothing else until it's done. 

The OP's 4K writes will be particularly badly performing.


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