Hallo Ramiro, Freitag, 13. Juni 2008, meintest Du:
RAQ> On Fri, 2008-06-13 at 17:55 +0200, Jan Heichler wrote: >> You can use the 24-port switches to create a full bisectional >> bandwidth network if you want that. Since all the big switches are >> based on the 24-port silicon this is no problem. RAQ> Yes, But How many ports must I waste if I do not want to loose to much RAQ> bandwidth. Exactly 50%. 12 Ports go to clients and 12 ports go to the spine. I can send you a sketch if you are interested. RAQ> And about latency, It could be negligible compared to latency at the RAQ> infiniband card (~3 microsecs in front of 480 nanosecs at switch), RAQ> right? The number of HOPs is always the same... 3 up to 288 ports. With the new 36 port silicon that will change. Up to 648 Clients with 3 HOPs if i'm not wrong. >> RAQ> c) Use the Flextronix 10U 144 Port Modular solution which will >> allow us >> RAQ> to scale well in a couple years >> But you have to pay now for an expansion that you might never get... >> Or want a fancy new network technology as soon as you upgrade. RAQ> Well, I most probably will be needing 48 ports in five months and 120 RAQ> ports in about a year 48 Ports is 6 24 Port Switches. here is a quick overview: client ports #of 24 port switches you need for full bisectional bandwidth 24 1 36 5 48 6 60 8 72 9 84 11 96 12 108 14 120 15 132 16 144 18 Somewhere around 11 and 14 is normally the break even for a 144-port switch - depends on your cost prices of course ;-) I hope i didn't miscalculate ;-) RAQ> Thanks for your answer Any time! Regards, Jan
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