Re: NIC on morollan
From: "Mitch Kutzko" <mitch@ncsa.uiuc.edu>
> At 01:52 AM 10/27/2004 +1000, Christoph Willing wrote:
> > Mitch,
> >
> > I see that you're the contact for morollan.ncsa.uiuc.edu - can you
> > confirm/deny whether its NIC uses the Intel e1000 chip? Its output in
> > the central_loss page shows a pattern of losses which we think can be
> > attributed to this driver/chipset.
> >
> > chris
>
> Hi, Chris -- Sorry to provide you with a "bad" data point for your theory,
> but here's the info for the NIC on morollan:
Perhaps this isn't a bad data point after all. Both the intel gigabit and
the 3com 3c905 tornado chipsets have support for tcp/udp checksum
offloading. In theory though, this should help improve responsiveness since
the host computer has to do less work processing the packets. I believe the
linux drivers support this offloading for both controllers. I know it is on
by default in the e1000 driver.
I have tried disabling the checksum offloading with the e1000 driver which
really did improve the pattern of loss visible on the central_loss page, but
didn't eliminate it entirely. I would have liked to have attributed the loss
to network conditions, but other hosts on the same subnet using a broadcom
gigabit chipset experienced no loss.
David Gwynne
>
> [root@morollan root]# cat /etc/sysconfig/hwconf
> [....]
> class: NETWORK
> bus: PCI
> detached: 0
> device: eth0
> driver: 3c59x
> desc: "3Com Corporation|3c905C-TX/TX-M [Tornado]"
> network.hwaddr: 00:04:75:AB:2A:5C
> vendorId: 10b7
> deviceId: 9200
> subVendorId: 10b7
> subDeviceId: 1000
> pciType: 1
> pcidom: 0
> pcibus: 2
> pcidev: c
> pcifn: 0
> [....]
>