Greg Lindahl wrote: > On Mon, Mar 12, 2007 at 03:16:43PM -0400, Robert G. Brown wrote: > >> I don't disagree, although even their earliest pictures had more than >> just CPU and memory hanging off the network. As in CPU, memory, a PCI >> bus and several direct attached devices were on most of the >> transparencies that I recall of AMD's roadmap presentation 2-3 years >> ago. > > We were around 2-3 years ago. But think: what on a typical motherboard > could be moved to HT that isn't aready there? Raid controller? gigE? > No, both of these find PCIe plenty fast. It's only exceptional devices > (video, high speed interconnect, coherant interconnect) that get a > benefit. > > Personally I've been kind of surprised that the video guys haven't > attached directly to HT. nVidia could have put their graphics chip in > their HT/PCIe bridge. I bet there's some economic reason that drives > it.
Because the unit volume that makes the parts profitable to fab is consumers putting $600 video-cards in $1000 pc's. Doing a one off for say a quadro 45xx variant (card that would retail for $5000) probably doesn't make sense... 40Gb/s is fast enough for their purposes right now... keeping the 128 stream processors in an 8800gtx fed is taking ~690Gb/s which is well outside what you can pull across a port you can find on a processor or north bridge anyway. >> You might want to edit the widipedia page on this, as it states >> "Hypertransport has largely fallen out of favor with the networking >> community, in favor of SPI 4.2 and PCI-Express" which definitely implies >> that at one time it was IN favor...:-) > > That's referring to the network community, as in ethernet switches. > There's a reason why SiByte and PMC Sierra and other folks have HT on > their non-x86 cpus. 10Gb/s ethernet is now being driven by the commodity space. pci-e 4x and 8x slots are adequate attachment points for 10Gb cards. The motivation for anything else is limited. > -- greg > > > _______________________________________________ > Beowulf mailing list, Beowulf@beowulf.org > To change your subscription (digest mode or unsubscribe) visit > http://www.beowulf.org/mailman/listinfo/beowulf > _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
