[ltp] USB Drive Transfer Rate

[Frank Schaeckermann]

mathieu.millet-at-ratp.fr |Linux on ThinkPads| wrote:
> 	Hi,
> 
> Be aware that all USB ports may not be connected to the same USB controller.
> 
> On my T40, the lower port is USB2.0 ans the upper one is USB1. For each, my
> Fedora loads a different module.

I tried both USB ports and in both cases the drive was found on 00:1d.7 
which lspci (see below) reports as the EHCI Controller thus USB 2.0 as 
far as I can tell:

00:1d.0 USB Controller: Intel Corp. 82801DB USB (Hub #1) (rev 01)
00:1d.1 USB Controller: Intel Corp. 82801DB USB (Hub #2) (rev 01)
00:1d.2 USB Controller: Intel Corp. 82801DB USB (Hub #3) (rev 01)
00:1d.7 USB Controller: Intel Corp. 82801DB USB EHCI Controller (rev 01)

00:1d.7 gets registered as bus 004 and lsusb reports:

Bus 004 Device 001: ID 0000:0000
Device Descriptor:
   bLength                18
   bDescriptorType         1
   bcdUSB               2.00 <---- version number?
   bDeviceClass            9 Hub
   bDeviceSubClass         0
   bDeviceProtocol         1
   bMaxPacketSize0         8
   idVendor           0x0000
   idProduct          0x0000
   bcdDevice            2.04
   iManufacturer           3 Linux 2.4.20-28.9custom ehci-hcd
   iProduct                2 Intel Corp. 82801DB USB EHCI Controller
   iSerial                 1 00:1d.7

But as I wrote before making sure the module usb-uhci wasn't loaded when 
attaching the drive I got a lot higher transfer rates. I haven't 
re-tested this behaviour yet though.

Frank