Hello Frank,
Thank you for replying.
Yes indeed, the Intel NIC is operating at 33MHz and 32 bit mode. From lspci
-v I had mistakenly concluded that the NIC was operating at 66MHz. It turns out
that the reason I had very high throughput earlier with the onboard NIC is that
the onboard NIC is connected directly to the southbridge chipset and therefore
does not compete with the slot based NICs for bandwidth. As a result it is
almost like having two separate PCI buses on a single system. I had not known
this fact. Only a perusal of some chipset / IO hub technical documentation
brought this to my attention. I confirmed this by testing with another PC's
onboard Gigabit NIC and an add-on GbE card.
So, with two Intel 82540EM Gigabit NICs on the PCI bus and some tweaking of
params, I never cross 410Mbps of routing throughput (about 820Mbps of PCI I/O
throughput). Guess the bad things people say about the PCI bus is true :-)
I will start searching for PCIe cards next time I want to build a Gigabit
router.
Thank you again.
Azeem Khan
Mumbai.
> From: f.da...@phion.com
> To: azee...@hotmail.com; e1000-devel@lists.sourceforge.net
> Date: Mon, 20 Apr 2009 08:54:14 +0200
> Subject: RE: [E1000-devel] Bitrate throughput for Gigabit capped around
> 300Mbps
>
> Hi Azeem!
>
> > I have a PC with an onboard NVIDIA GbE NIC, an Intel 82540OEM NIC and an
> > Intel 82545EM NIC in PCI slots.
>
> If it's in a PCI slot, could you please have a look in dmesg at the point
> where the e1000 driver module loads and could you check which kind of PCI
> interface the driver uses?
>
> Should look like this:
>
> > Intel(R) PRO/1000 Network Driver - version 7.6.15.5-NAPI
> > Copyright (c) 1999-2008 Intel Corporation.
> > PCI: Setting latency timer of device 01:00.0 to 64
> > e1000: 01:00.0: e1000_probe: (PCI Express:2.5Gb/s:Width x4)
> > 00:10:f3:0e:c5:d4
>
> If it's only operating in PCI 33Mhz, 32 bit mode you'll never get more
> throughput than 300 - 400 mbit/s
>
> Frank
_________________________________________________________________
So many new options, so little time. Windows Live Messenger.
http://www.microsoft.com/india/windows/windowslive/messenger.aspx
------------------------------------------------------------------------------
Stay on top of everything new and different, both inside and
around Java (TM) technology - register by April 22, and save
$200 on the JavaOne (SM) conference, June 2-5, 2009, San Francisco.
300 plus technical and hands-on sessions. Register today.
Use priority code J9JMT32. http://p.sf.net/sfu/p
_______________________________________________
E1000-devel mailing list
E1000-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/e1000-devel
