Re: Slow ethernet/NE2000 with all 1.3 kernels (1.2 is fine)

Paul Gortmaker (gpg109@rsphy6.anu.edu.au)
Wed, 8 May 1996 13:21:32 +1000 (EST)


>From "Jamie Lokier" at May 7, 96 11:07:00 pm

> As I reminder, I wrote:
>
> >> Where I work, all our PC ethernet cards are NE2000 clones of one
> >> sort or another. I know NE2000's aren't supposed to be the
> >> fastest cards around, but back in the days of 1.2 kernels,
> >> `tcpspray' was able to send about 900k/s to an SGI, and about
> >> 850k/s to another, identical Linux box. There was some variation
> >> between cards from different manufacturers (and versions), with
> >> some getting as low as 780k/s (ish).

[...]

> >> To summarise: 1.2.x kernels -> 900k/s TCP data transmission rate
> >> 1.3.x kernels -> 700k/s TCP data transmission rate

Jamie, where have you been in the past week or so? <grin>
Did you completely miss the thread "Tx TCP rates down > 20% - A report" ?

(If so, go to http://www.linux.ncm.com and have a browse, as it is
better than having you mailbox spammed anyways...)

In short, there was a problem associated with the modularization done
way back in 1.3.1x kernels that caused 8390 based cards to Tx at least
20% slower than they are capable (regardless of whether you are using
the 8390 code as a module or not). I have fixed it for 1.3.99, and my
measurements indicate that Tx rates are back to 1.2.x levels or better.
Note that Rx rates were unaffected, which is why probably why the
problem went unnoticed for the last seven months.

Paul.