No matter what API you're using (SMP/threads or Beowulf/PVM) these are most likely best used for SIMD (single-instruction, multiple-data) kinds of problems (of which SETI is one). Communication between boards will be a major performance bottleneck, since they all share the same bus.
Since they do have local RAM (and not just cache), you load the card's RAM with one set of code and four sets of data. Do that for all the cards you have. Now wait, and get your answers back off the local RAM. Did you use threads or processes? Threads and its closer to SMP, processes and it is closer to PVM or Beowulf.
But will it outperform a comparable Beowulf cluster? If it is compute-constrained, then the PCI cards will do better, especially as the problem scales, because the PCI cards share hardware costs for disks, network cards, fast bus, large RAM, etc. If it is disk or network limited, though, the Beowulf will eventually win out. The PCI cards will do well on a price/performance basis while the problem is small, because it will still be sharing hardware. But once the PCI bus fills up, those processors will start waiting on the bus. The bigger the problem gets, the more the processors wait. The Beowulf cluster, on the other hand, can distribute all that hardware - instead of one 100Mbps network card, it may have dozens (you start worrying more about what your ethernet switch's backplane looks like).
So these cards are best for compute-intensive simulation-style stuff (image filters would also scream - mostly - FFTs require lots of communication). Simulated wind tunnels or weather phenomena, finite-element analysis, etc.
Note though, that these cards have their own slower PCI bus, including support for an add-on card (!), so conceivably you could get a lot of server oomph by giving every four processors their own network card. But you better make sure you data (i.e., your web site) can fit in the local RAM, or you'll bog down in bus contention again.
Does anyone else find it interesting that the Farber Institute solicits donations from movie audiences nation-wide? In fact, you are donating directly to the FCC, which your tax dollars already pay for. Interesting, no ?
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No matter what API you're using (SMP/threads or Beowulf/PVM) these are most likely best used for SIMD (single-instruction, multiple-data) kinds of problems (of which SETI is one). Communication between boards will be a major performance bottleneck, since they all share the same bus. Since they do have local RAM (and not just cache), you load the card's RAM with one set of code and four sets of data. Do that for all the cards you have. Now wait, and get your answers back off the local RAM. Did you use threads or processes? Threads and its closer to SMP, processes and it is closer to PVM or Beowulf. But will it outperform a comparable Beowulf cluster? If it is compute-constrained, then the PCI cards will do better, especially as the problem scales, because the PCI cards share hardware costs for disks, network cards, fast bus, large RAM, etc. If it is disk or network limited, though, the Beowulf will eventually win out. The PCI cards will do well on a price/performance basis while the problem is small, because it will still be sharing hardware. But once the PCI bus fills up, those processors will start waiting on the bus. The bigger the problem gets, the more the processors wait. The Beowulf cluster, on the other hand, can distribute all that hardware - instead of one 100Mbps network card, it may have dozens (you start worrying more about what your ethernet switch's backplane looks like). So these cards are best for compute-intensive simulation-style stuff (image filters would also scream - mostly - FFTs require lots of communication). Simulated wind tunnels or weather phenomena, finite-element analysis, etc. Note though, that these cards have their own slower PCI bus, including support for an add-on card (!), so conceivably you could get a lot of server oomph by giving every four processors their own network card. But you better make sure you data (i.e., your web site) can fit in the local RAM, or you'll bog down in bus contention again.
Ahhh, near Worcester ? :)
Does anyone else find it interesting that the Farber Institute solicits donations from movie audiences nation-wide? In fact, you are donating directly to the FCC, which your tax dollars already pay for. Interesting, no ?
try SMT Technical Overview
Take a look at some of the reader reviews here. An essay on some of the same material is also available here for those of you who are interested.