FYI, some vendor called Unity Electronics is currently selling a bunch of 24 port SMC 8524T gigabit switches for c. $120 each on Ebay:
http://search.ebay.com/search/search.dll?satitle=SMC+gigabit&sass=unityelectronics.com http://unityelectronics.com/product-product_id/3942/m/SMC/p/SMC8524T http://unityelectronics.com/product-product_id/3941/m/SMC/p/SMC8516T I haven't actually tried using it yet, but the one I recieved is part number 751.7398, and appears to be new in box as advertised. And that reminded me of the interesting thread from April, below, on performance testing of some (small) SMC gigabit switches: http://www.beowulf.org/archive/2007-April/017924.html On Mon, Apr 02, 2007 at 03:58:06PM -0500, Bruce Allen wrote: > Subject: Re: [Beowulf] How to Diagnose Cause of Cluster Ethernet Errors? > Just for kicks have a look at these figures: > http://www.lsc-group.phys.uwm.edu/beowulf/nemo/design/SMC_8508T_Performance.html > Here are some more testing results from different edge switches: > http://www.lsc-group.phys.uwm.edu/beowulf/nemo/design/switching.html Bruce, it's interesting how your bandwith tests show the SMC 8508T 721.0154 switch started out with true wire-speed and 9k jumbo frame performance, 721.8129 was worse, and then 722.8486 was yet worse again. Compared to the previous part number, each subsequent revision of the supposedly "same" SMC8508T model degraded performance! And your tests were with only 2 of the 8 ports on each switch, so I wonder how much worse they'd be when using all ports at once. It's also interesting that all 3 part numbers showed the same performance for the 2 kb MTU. The iterative cheapening of the hardware seems to have only broken the large frame sizes. However, I'm confused by part of your results: Some of your crossover cable and 5 port switch results show a big bandwith advantage when using jumbo frames - bandwith takes a huge jump up from around 125 MB/s with a 2k MTU to 225 with 4k. But your 8508T results, on the other hand, are much better at 2k, around 200 MB/s, and then gradually moves up to about the same 225 at 4k. Any idea why you saw those different behaviors? -- Andrew Piskorski <[EMAIL PROTECTED]> http://www.piskorski.com/ _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
