Usb drive performance



I have connected external usb drive and the performance in guest is way below expectations. hdparm -t reports 2MB in 5 sec.
The same drive connected to host reports: 90 MB in 3.05 seconds = 29.49 MB/sec
I start the kvm with:
sudo kvm -enable-kvm -boot d -vga vmware -hda disk0 -cdrom ~/download/iso/systemrescuecd-x86-1.2.3.iso -usb -usbdevice host:1058:0704

host uname -a reports: Linux pecet 2.6.31-17-generic-pae #54-Ubuntu SMP …
guest: Linux sysrescuecd #1 SMP …

kvm version is whatever comes with ubuntu (QEMU PC emulator version 0.11.0 (qemu-kvm-0.11.0))

Do I have to do anything extra on the host? Until now I simply unmounted whatever got mounted in /media before starting the kvm