USB Performance and configuration...

[Howard Woodard]

I have a Sony Vaio desktop that has 4 USB 2.0 connectors on the back and 2
USB 2.0 connectors on the front. I've noticed that I'm getting nowhere near
the 480 mbps throughput of a 2.0 device. In fact, I'm lucky to get more
than about 4.5 mbps with 1.5 mbps being fairly common as well. The devices
are external USB drives and the performance that I'm referring to is the
transfer rate that is reported during a file transfer.

I looked at the Device Manager, expecting to see something that looks like 6
USB ports. What I see is:
**Universal Serial Bus controllers**
- SiS 7001 PCI to USB Open Host Controller (System Reserved 10% bandwidth)
- SiS 7001 PCI to USB Open Host Controller (System Reserved 10% bandwidth)
- SiS 7001 PCI to USB Open Host Controller (System Reserved 10% bandwidth)
- Standard Enhanced PCI to USB Host Controller (System Reserved 20%
bandwidth)
- USB Mass Storage Device
- USB Root Hub (full speed)
- USB Root Hub (full speed)
- USB Root Hub (full speed)
- USB Root Hub (high speed)

The only USB device connected at the moment is a 4 gb USB flash drive in one
of the two front connectors and configured for use by ReadyBoost.

Do any of you folks know:
(1) how the devices [in Device Manager] above relate to the physical
connectors (4 rear/2 front)?
(2) how the bandwidth gets assigned to the host controllers and whether it
can be changed or not?
(3) why the hubs report less than high speed and whether that can be changed
or not?

Thanks in advance,

Howard

 

[Howard Woodard]

Any USB experts out there?

=====================================