perfSONAR User Q&A and Other Discussion

[Joseph Bernard <>]

Broadcom NetXtreme BCM5721


On 2/14/12 2:30 PM, "Brian Tierney" 
<>
 wrote:

>
>
>interesting.
>
>what type of NIC is in this host?
>
>
>On Feb 14, 2012, at 11:20 AM, Joseph Bernard wrote:
>
>> 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
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>> 
>>> 
>> 
>