----- Original Message ----- | On Dec 10, 2011, at 1:49 PM, "James A. Peltier" <jpeltier at sfu.ca> | wrote: | | > Jumbo frames is really the important thing when it comes to iSCSI. | > Having 9000 byte packets verses 1500 byte packets will dramatically | > increase your performance per interrupt. Most cheaper unmanaged | > switches cannot do this. | | I want to break the myth here, jumbo frames are really only important | for 10Gbe+. On 1Gbe (or slow CPUs) they actually slow sequential | throughput due to the time to process each packet on 1Gbe and how that | in turn slows down packet interleaving and thus total throughput. | | -Ross On cheap network switches... When you've got a switch that has 1 or more 10Gb uplinks and the rest of the switch is Gb, I doubt this is an issue, but I will agree that on *some* switches it may be detrimental to performance. -- James A. Peltier Manager, IT Services - Research Computing Group Simon Fraser University - Burnaby Campus Phone : 778-782-6573 Fax : 778-782-3045 E-Mail : jpeltier at sfu.ca Website : http://www.sfu.ca/itservices http://blogs.sfu.ca/people/jpeltier I will do the best I can with the talent I have