Cisco switches for lam mpi
Gerry Creager N5JXS
gerry.creager at tamu.edu
Mon Aug 4 09:50:09 EDT 2003
I should have commented earlier, but I didn't think I had time...
My experience with the Cisco 4006 was that as an aggregation switch it
was OK for 10/100 or GBE. It did fine for normal "enterprise switching.
The 4006's I've used had only older Supervisor Modules and ran CAT-OS,
rather than IOS like the 4506 I'm testing now.
For higher performance, while CPU utilization stays low, the switch
falls off at higher loads.
Caveat: I did not test these devices in a cluster environment; the
thought never crossed my mind. I'd be using a 6509 if I had to use a
Cisco, but I'd probably be shopping for HP ProCurves, Foundry's,
Riverstones, or NEC Bluefires, based on what I've seen and done lately.
I tested the 4006 in normal enterprise mode, and loaded it for
high-perf network modes. If you ever need QoS do NOT use a 4006. Or a
4506. They can't handle it too well. But I digress.
I'm gonna try to get a couple of ProCurves in and test 'em against a LAN
tester made by Anritsu (MD1230/1231) for small packet capability
(RFC-2544). That's been a killer for a lot of switches I've looked at.
Felix Rauch wrote:
> On Tue, 29 Jul 2003, Jack Douglas wrote:
>>We have just installed a 32 Node Dual Xeon Cluster, with a Cisco Cataslyst
>>4003 Chassis with 48 1000Base-t ports.
>>We are running LAM MPI over gigabit, but we seem to be experiencing
>>bottlenecks within the switch
>>Typically, using the cisco, we only see CPU utilisation of around 30-40%
> I'm not a Cisco expert, but...
> We once got a Cisco switch from our networking people that we had to
> return immediately because it delivered such a bad performance. It was
> a Catalyst 2900XL with 24 Fast Ethernet ports, but it could only
> handle 12 ports at full speed. Above that, the performance brake down
> For some benchmark results see, e.g.:
> As a comparison, the quite nice results of a CentreCom 742i:
> Disclaimer: Maybe the Cisco you mentioned is better, or Ciscos improved
> anyway since spring 2001 when I did the above tests. Besides, the
> situation for Gigabit Ethernet could be different.
> As we described on our workshop paper at CAC03 you can not trust the
> data sheets of switches anyway:
> Conclusion: If you need a very high performing switch, you have to
> evaluate/benchmark it yourself.
> - Felix
Gerry Creager -- gerry.creager at tamu.edu
Network Engineering -- AATLT, Texas A&M University
Cell: 979.229.5301 Office: 979.458.4020 FAX: 979.847.8578
Office: 903A Eller Bldg, TAMU, College Station, TX 77843
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