Subject: USB ethernet performance
To: None <>
From: Laine Stump <>
List: current-users
Date: 03/17/2000 17:06:56
I just received my SMC "EZNET-USB-10/100" ethernet ($29 from
and plugged it in. As expected, it is detected as aue0, and works just
fine (didn't even have to reboot. Cool Beans!!)

Performance seems overly limited, however. I have the adapter plugged
into a 10/100 hub (yes, its detected as 100, and ifconfig reports that
too), and another NetBSD machine plugged into the same hub. When I run
ttcp for 32Mbytes, between the USB ethernet and the other machine (which
has a tlp card), I only get 415 KBytes/sec receive, or 460Kbytes/sec
send. On the other hand, if I do ttcp between the same two machines, but
using PCI ethernet cards instead, I get 9383Kbytes/sec receive and
7819Kbytes/sec send. I knew I couldn't expect anything much over
10Mbits, but somehow I hoped for more than this.

Is this kind of throughput normal for 10/100 USB adapters? If not, any
ideas where I should start looking for the problem? (For starters,
netstat -ni shows 0 errors/collisions).