Mark Hahn wrote: > I don't follow why that indicts latency - multiple smaller packets don't > each require a round trip, for instance. with TCP, I've only > ever seen jumbo packets resulting in modestly higher bandwidth and often > noticibly lower CPU overhead. TCP with 1500B packets will _certainly_ > have multiple packets in flight, so on a lan is not terribly > latency-sensitive. > > if this traffic is to some hotspot, I'd be more inclined to think that > small packets are overloading the CPU with interrupt and TCP-stack > overhead.
True. I guess I'm leaning toward latency because I don't see bandwidth as being the issue - if the overhead is lots of small packets overloading the CPU shouldn't I see a lot of system time on some nodes? >> looking for. Do you eyeball raw tcpdump data or use wireshark to >> browse it? > > I use perl to browse it ;) Hehe, fair enough. I am well versed in the art of perl hacking, just not sure it's the best way to use my analysis time. > pricing is always squishy for this category of hardware. you can see > the myrinet list prices on the myricom website. for 16 ports: > 16*(495+75)+6600 > comes to just under $1k/port. using local (Canadian) HP public-sector > prices, IB is $1600/port. I'd be surprised of both couldn't be bettered. Thanks - interesting to get even this kind of comparison, I'm sure its in the right ballpark anyways. -stephen -- Stephen Mulcahy, Applepie Solutions Ltd, Innovation in Business Center, GMIT, Dublin Rd, Galway, Ireland. http://www.aplpi.com _______________________________________________ Beowulf mailing list, [email protected] To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
