Low perfomance when read from usb flash drive

[Artyom Mirgorodsky]

> Here is a patch which I think will address your problem. It is EHCI hardware 
> related. Different models behave differently. Try this:
> 
> http://perforce.freebsd.org/chv.cgi?CH=158692

Much better:

dd if=/dev/da0 of=/dev/null bs=64k count=5000
5000+0 records in
5000+0 records out
327680000 bytes transferred in 17.282871 secs (18959813 bytes/sec)