perfSONAR User Q&A and Other Discussion

[Joseph Bernard <>]

One more thing I've noticed.  When I do TCP in PS-PS, the server side CPU
gets to 80%.  When I do UDP, the CPU only gets to 45%.  On CentOS 5.7, the
CPU goes to 20% on TCP and 99% on UDP.


Thanks,
Joseph


On 2/14/12 11:30 AM, "Joseph Bernard" 
<>
 wrote:

>I used the -w option and got closer to 700Mb/s. I even put it at 64M to
>see if it made a difference.  I decided to install CentOS 5.7 i386 and got
>950Mb/s on both TCP and UDP, and the limit with the -w option is 256
>Kbyte.  Now I'm not sure if PS-PS is slower or if CentOS 5.7 is less
>accurate.
>
>
>Thanks,
>Joseph
>
>
> 
>
>On 2/13/12 5:13 PM, "Brian Tierney" 
><>
> wrote:
>
>>
>>Did you use the -w option with UDP?
>>
>>TCP autotunes, UDP does not, and to go fast UDP needs more buffer space
>>than the default.
>>
>>Try adding "-w 4M" to both sender and receiver.
>>
>>On Feb 13, 2012, at 1:35 PM, Joseph Bernard wrote:
>>
>>> I loaded 3.2.1.1 on 2 workstations and got 950Mb/s on TCP and 600Mb/s
>>>on
>>> UDP tests.  They both have 1Gb/s cards.  I thought maybe the network
>>>cards
>>> weren't up to snuff, so I got 2 HP servers, loaded them up, and did the
>>> same tests.  I got the same results.  The workstations/servers are
>>> connected via crossover.  I even tried a brand new cable to be sure it
>>> wasn't bad materials.
>>> 
>>> When I used my iMac and Macbook Pro from 2009 running Snow Leopard, I
>>>was
>>> able to get 800Mb/s running iperf.  Is there something I am missing?
>>> 
>>> 
>>> Thanks,
>>> Joseph Bernard
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>
>