bad performance of aue device when used with nVidia nForce MCP79 USB

[Marcus Müller]

Hi all!

I need some advice how to best tackle this problem I'm having with an ADMtek USB To LAN Converter in conjunction with an nVidia nForce MCP79 USB chip:

--- config begin ---
root at creutzfeld:(~)# uname -a
FreeBSD creutzfeld.z.net 8.2-STABLE FreeBSD 8.2-STABLE #7 r226546: Wed Oct 19 22:08:28 CEST 2011     root at creutzfeld:/usr/obj/usr/src/sys/CREUTZFELD  amd64
root at creutzfeld:(~)# usbconfig list
ugen0.1: <OHCI root HUB nVidia> at usbus0, cfg=0 md=HOST spd=FULL (12Mbps) pwr=SAVE
ugen1.1: <EHCI root HUB nVidia> at usbus1, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=SAVE
ugen2.1: <OHCI root HUB nVidia> at usbus2, cfg=0 md=HOST spd=FULL (12Mbps) pwr=SAVE
ugen3.1: <EHCI root HUB nVidia> at usbus3, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=SAVE
ugen3.2: <USB To LAN Converter ADMtek> at usbus3, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=ON
ehci1: <NVIDIA nForce MCP79 USB 2.0 controller> mem 0xfae7e800-0xfae7e8ff irq 21 at device 6.1 on pci0
--- config end ---

This ADMtek device gets roughly 10MBit downstream with the configuration above. When used with the same OS on a board with an Intel 82801GB/R (ICH7) USB 2.0 controller it gets 64MBit downstream, which is the maximum I can get from my ISP.

I don't see anything unusual in the system messages, thus I suspect it's an issue with the USB implementation for the nForce chipset.

What can I do in order to find out what's the bottleneck here?


Thanks in advance,

  Marcus