David Miller wrote:
quoted text
> From: Jesper Krogh <jesper@krogh.cc>
> Date: Fri, 09 May 2008 23:59:18 +0200
> 
>> David Miller wrote:
>>> From: Jesper Krogh <jesper@krogh.cc>
>>> Date: Fri, 09 May 2008 20:32:53 +0200
>>>
>>>> When it works I doesnt seem to be able to get it pass 500MB/s.
>>> With this card you really need multiple cpus and multiple threads
>>> sending data through the card in order to fill the 10Gb pipe.
>>>
>>> Single connections will not fill the pipe.
>> The server is a Sun X4600 with 8 x dual-core CPU's, setup with 64
>> NFS-threads. The other end of the fiber goes into a switch with gigabit
>> ports connected to 48 dual-core cpus. The test was done doing a dd on a
>> 4.5GB file from the server to /dev/null on the clients.
> 
> A single file transfer will not fill the pipe using this card, no
> matter how many cpus you have :-)

I do run 20+ times dd on each of the clients at the same time. Using a
single client I should be able to get it pass 1 gigabit. (The 4.5 GB
file can fit in the 32GB memory of the server so the serverdisk isn't
the bottleneck either)

Further investigation shows that:
# ethtool -k eth4
Offload parameters for eth4:
Cannot get device rx csum settings: Operation not supported
rx-checksumming: off
tx-checksumming: on
scatter-gather: on
tcp segmentation offload: off
udp fragmentation offload: off
generic segmentation offload: off

Does that seem correct?

-- 
Jesper
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