USB 3.0 transfer speeds on Linux

posted on 10:44 PM on Thursday 12 December 2013

Thinking that USB 3.0 might be a reasonable way to attach lots of drives, I got a USB 3.0 portable 2.5" 1TB drive from Seagate to test its transfer speed. The following is the bonnie++ output from the Seagate drive connected to USB 3.0 in Linux:

Version  1.96       ------Sequential Output------ --Sequential Input- --Random-
Concurrency   1     -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
bob             31G   981  94 72831   9 39674   5  4059  94 117863   6 114.7   1
Latency             14671us     901ms     887ms    9356us     161ms   64699ms
Version  1.96       ------Sequential Create------ --------Random Create--------
bob                 -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
                 16 14349  10 +++++ +++ 10884   5 26680  17 +++++ +++ +++++ +++
Latency             14111us     470us     538us     288us      27us     570us

This is the output from the eSATA connected ZFS pool:

Version  1.96       ------Sequential Output------ --Sequential Input- --Random-
Concurrency   1     -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
bob             31G   172  99 93448  11 61622  11   419  98 182779  11 191.6   7
Latency             74909us   12032us     903ms   94470us     316ms     233ms
Version  1.96       ------Sequential Create------ --------Random Create--------
bob                 -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
                 16 11745  45 +++++ +++ 16822  55 11020  50 +++++ +++ 14196  53
Latency             30405us     509us     292us   47021us      24us    2572us

It is clear that the eSATA ZFS pool is faster but not by that much. Write speeds are nearly the same but read speeds are rather different. One factor against the USB 3.0 is that it is probably a slow disk. But the eSATA ZFS pool is connected to a 1x PCIe so it takes a hit too. All in all, not a bad performance from the USB 3.0 drive. For folks who favour ease of connection, USB 3.0 might not be too bad.

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