Re: [E1000-devel] Bug report E1000 driver bonding in 802.3ad mode can not go beyond 1GB/s throughput

[Support T. <su...@ca...>]

Hi Mitch,

I will have to have someone here to help me get both lspci -vvv for you.

To be clear, let me state it again, the 82573 NICs based system is dual core
1.6GHz CPU 
system; The 82546 based on Dual Xeon 3.6GHz with PCI-X 133 66it buses
designed to have
PCI-X buses on the north bridge.  

I hope I am not that stupid to expect 33bit PCI bus to get many gigabits
throughput.

When I apply the load, the 82573 based setup scale up well. When I apply
1GB/s load, it
will get 1GB/s throughput; when I apply 2GB/s load, it will pass 2GB/s
throughput.  For
the 82546 chip, When I apply 1GB/s load, it gets 1GB/s load at 25% CPU
usage. When I
apply 2GB/s load, it still passes 1GB/s throughput at 50% CPU usage.  When I
apply 3GB/s load,
it still passes 1GB/s throughput at 80% CPU usage.  Software setup on both
system are the
same way. Only difference is 82573 uses E1000E driver and 82546 uses E1000
driver.

Thanks!
Wayne

-----Original Message-----
From: Williams, Mitch A [mailto:mit...@in...] 
Sent: Friday, March 27, 2009 2:47 PM
To: su...@ca...; 'Jay Vosburgh'
Cc: e10...@li...; Ronciak, John
Subject: [work] RE: [E1000-devel] Bug report E1000 driver bonding in 802.3ad
mode can not go beyond 1GB/s throughput

>is why E1000E driver and 82573 NIC bonding can get 2GB/s with two NIC
>bonded, but Pro/1000 MT server
>adapter cannot break the 1GB/s limit.  We actually tried also 
>with CentOS
>5.2, it seems true for that
>also -- E1000 driver with 82546 NICs bonding in 802.3ad cannot 
>get more than
>1GB/s through it.  the tests
>are with same clients, same servers, same switch, and same 
>network cable
>wires.

Please send a dmesg log and the output of lspci -vvv on both configurations.

The 82573 is a PCI-Express part, and the 82546 is a PCI-X part.  Most newer
systems that support PCI-Express have fairly limited bandwidth for their
PCI slots.  It may be that you're running into a bus bandwidth issue.

If your two 82546 boards are in 32-bit slots in a shared bus you will 
never get 2 GB/s out of them no matter what you do.

-Mitch