[vortex-bug] Asymetric throughput with 3c905b NIC

[Ted Matsumura]

Do you have any tests results where you are sending from RH 2.2 kernal to RH
2.2 kernal?

If this is an "OK" #, then the driver is apparently optimized for the RH 2.2
kernal, and/or the RH 2.2 kernal is optimized for "OK" throughput.

You may need to tweak vanilla kernal xxx OS and/or drivers to get "OK" data
with the vanilla kernals.

Ted

> -----Original Message-----
> From: vortex-bug-admin@scyld.com [mailto:vortex-bug-admin@scyld.com]On
> Behalf Of Céline and Régis Duchesne
> Sent: Thursday, June 29, 2000 11:29 PM
> To: linux-kernel@vger.rutgers.edu; vortex-bug@scyld.com
> Subject: [vortex-bug] Asymetric throughput with 3c905b NIC
>
>
> Hi,
>
> I'm have 2 machines (A and B), both Pentium II 300 Mhz equipped
> w/ a 3c905b
> (cyclone) NIC, linked together w/ a cross-over cable.
>
> I use "ttcp" to measure the TCP throughput between them. Unfortunately, it
> seems that this measure is asymetrical. I get the following results:
>
> "->" means that the machine on the left sends the TCP payload,
> and that the
> machine on
> the right receives it.
>
>           Machine A                    Machine B            Result (Mb/s)
>           ---------                    ---------            -------------
> 0) vanilla kernel 2.2.14      -> RedHat kernel 2.2.12-20    OK  (93)
> 1) vanilla kernel 2.2.14      <- RedHat kernel 2.2.12-20    Bad (50)
>
> 2) vanilla kernel 2.4.0-test1 -> RedHat kernel 2.2.12-20    OK  (94)
> 3) vanilla kernel 2.4.0-test1 <- RedHat kernel 2.2.12-20    Bad (39)
>
> 4) vanilla kernel 2.4.0-test1 -> vanilla kernel 2.4.0-test1 Bad (18)
> 5) vanilla kernel 2.4.0-test1 <- vanilla kernel 2.4.0-test1 Bad (25)
>
> 6) vanilla kernel 2.2.12      -> vanilla kernel 2.4.0-test1 Bad (37)
> 7) vanilla kernel 2.2.12      <- vanilla kernel 2.4.0-test1 OK  (94)
>
> 8) vanilla kernel 2.2.12      -> RedHat kernel 2.2.12-20    OK  (93)
> 9) vanilla kernel 2.2.12      <- RedHat kernel 2.2.12-20    Bad (40)
>
> This experiments are perfectly reproducible.
> As you can see in 2) and 7), this is not a defect in the cross-over cable.
> It seems to be only related to the driver versions I use.
> Whatever the throughput is, ifconfig eth0 doesn't report any error or
> collision.
>
> A friend of mine told me that he solved a similar problem by using 3Com's
> driver for this card, instead of Donald (and al.)'s one. I couldn't verify
> this, because I can't "ifconfig eth0 up" with 3Com's driver (it reports
> "SIOCSIFFLAGS: No such device", which sounds silly
> since it does a SIOC_G_IFFLAGS right before that, with the same device
> name...).
>
> Does anybody have a clue what's going on here? I can provide
> vortex_probe(),
> mii-diag outputs if needed, and I'm ready to test any patch you will send
> me.
>
> Please reply to hpreg@vmware.com, as I'm not subscribed to any of those
> lists, and I have no idea how the hell I can teach Outlook Express how to
> send a "Reply-To:" field :)
>
> Thanks for reading, and thanks in advance for your help,
> --
> Régis "HPReg" Duchesne
> Member of Technical Staff
> http://www.vmware.com/
>
>
>
> _______________________________________________
> vortex-bug mailing list
> vortex-bug@scyld.com
> http://www.scyld.com/mailman/listinfo/vortex-bug
>