Lamar Owen wrote: > On Saturday, February 19, 2011 10:13:08 pm Chris Smart wrote: >> So that ran at about 35MB/sec, which is probably what I'd expect on a >> USB2.0 drive anyway. > >> What would be interesting, is if you repeated the test after taking >> the drive out of the USB 3.0 enclosure and putting it into a USB 2.0 >> one.. > > The easier thing is to connect the USB3 cable from the drive to a USB2.0 port > (the PC side of a USB3.0 cable is downwards compatible; the device side > connectors are not). Speed halves when I do that; re-rsyncing everything > (all 246GB; I removed it all (I literally zeroed out the drive, remade the > ext4 filesystem), and started from scratch)) took almost exactly twice as > long, 5 hours and 14 minutes. > > The large number of small files in my .kde tree (mail, for one) slows things > down; the VMware .vmdk's give a better indication of the true throughput of > the drive. > > USB2's absolute max sustained speed on most EHCI implementations is ~32MB/s; > even the average 35MB/s of the initial USB3 rsync is beyond that reach by > 3MB/s, and that included the 195,000 files (consuming 6.7GB) that is my .kde > tree. And then the development tree, with a number of svn checkouts: 422,000 > files in 6.8GB of space. That sort of 'lots of small files' situation really > slows down the transfer rate for rsync.
Depending on your drive, you may be able to improve that a bit by setting the max_sectors for the device higher. /sys/blockdev/sdX/device/max_sectors (from memory). -- Bill Davidsen <david...@tmr.com> "We have more to fear from the bungling of the incompetent than from the machinations of the wicked." - from Slashdot -- users mailing list users@lists.fedoraproject.org To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines
