> At least with the Phi, within a single system, its completely >cache-coherent... all 60 cores (240 hardware threads).
well, hardware-managed, so it's still time-slicing the core's resources. (one FPU per core, for instance.) > Am I stupid in thinking that they would also make very interesting web > applications servers - get your database on a solid state array > Beside the Phi and crank up those web servers. sure. in HPC terms, webserving is usually just cache-friendly serial farming, and scaling it is really just a matter of providing lots of modest-speed integer-based CPUs with decent amounts of memory bandwidth. Phi only has 8GB ram, which for 60 real cores or 240 timesliced ones, is not that much. 320GB/s theoretical is 5.3 GB/s/core - not all that great either, but decent considering this is a many-slow-cores approach. (for comparison, Calxeda puts 4x 1.4GHz arm cores on a ddr3 dimm - probably 2.7 GB/s/core, but a lot higher ram capacity/core.) I don't know how well Phi manages IO, but its 16x PCIe v2 interface has a theoretical peak of 8GB/s each way, which seems plenty as long as the 8G ram onboard has a decent hit rate. my guess is it would make a great webserver except for the 8G limit. _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
