dd on USB 2.0 device (OHCI) horrible slow

Sun Jul 2 21:41:03 UTC 2006

Hello.
Tried today to delete and prepare a fresh installed external USB 2.0 
drive as GELI provider, here is the result of an aborted dd:

sotokan# dd if=/dev/random of=/dev/da0a.eli bs=16k
^C8388825+0 records in
8388824+0 records out
137442492416 bytes transferred in 33883.288406 secs (4056350 bytes/sec)

system is a FreeBSD 6.1-STABEL/amd64 box, hardware ASUS A8N32-SLI Deluxe 
with AMD64 3500+