Comment 154 for bug 197762

This isn't normal behavior. Obviously it behaves fine while all writes are going to buffer cache, but once it tries to write it out to the device, wait times on the partition shoot up to 30sec or more, and all processes trying to touch the usb disk block practically forever. Sysstat shows it as 100% busy continuously. The reports of "Fast at first, then slowing down" are of course because of the buffer cache making it look like it's initially "fast" but access to the underlying device is always very slow, whether you are writing to it with gvfs, cp, dd, buffer, or whatever.

The usb storage device *is* being claimed by ehci, not uhci, which I initially suspected was the problem. (btw the decision to compile the uhci-hcd and ehci-hcd drivers rather than leave them as modules, I think, is a bad one, since it eliminates the possibility of removing uhci-hcd to force ehci-hcd to claim a driver, as is sometimes necessary)

In addition, it's only writes that are slow, and they're vastly slower than could be explained by a crappy USB device- in my case around 100 - 200 kbytes/sec on a device that under a Hardy install writes at several mbytes/sec.

In my case this is happening on an lenovo X61 (intel) 2.6.28-11-generic.