is USB in general known to slow down system performance, or is it only some particular devices that do that? I have cable modem that can be conected to the computer via USB or via Ethernet. When connected via USB memory-chipset-CPU benchmark is about 15% slower then when connected via ethernet. Network speed is about the same as far as I can see either way.
PIII450 (run at 504MHz)
Tyan trinity 400 MOBO
Network everywhere NIC (10/100)
Motorolla SurfBoard4100 cable modem