In June/08 I talked to Joost Batenburg, one of the researchers
who uses the FASTRA system (at the time they were looking
into better cooling solutions and I had some suggestions).
The important point about this system is that it does not
involve any communication between the GPUs, ie. SLI is
irrelevant. Indeed, the gaming 3DMark06 score for the system
is not that high, partly because it's only really using one
card for the test (the mbd is a Crossfire board, chosen for
Indeed, after it was first announced, some people asked why
they didn't use 9800GTX cards instead of 9800GX2s. The GTX
is faster for games, but not by much, whereas the tomography
computations the researchers are doing can fully use both
GPUs on a GX2 card, giving a virtually perfect linear scaling
for multiple GPUs, ie. much better than a GTX card.
Oddly enough, there *is* a commercial system that can use
up to 8 gfx cards (ie. 16 GPUs), namely SGI's top-end VS
system (up 8 quad-core Opterons, 8 x PCIe cards, 256GB RAM),
which is a rebadged version of the top-end system from BOXX.
However, FASTRA is cheaper, and they don't need much in the
way of main-CPU power anyway so a system supporting lots of
normal CPUs would be a waste.
FASTRA is interesting because of how it is used, but a bit
strange that toms would put it into the list since it's not
a games machine.
Btw, the researchers' previous 'device', as toms puts it,
was a cluster of 256 dual-core Opterons.
Wow in SA we hardly even hear about stuff like that, and why would they run a Phenom in there, a Core i7 SLAUGHTERS it in its dreams! I mean even the Phenom II is weak compared to the Core i7, even the 920 model outruns anything AMD have to offer which is extemely sad
Read the article and the references I mentioned. The
processing the researchers are doing does not require a good
main CPU (it's all done on the GPUs via CUDA). An i7 is
totally unnecessary for their needs. Besides, they needed a
mbd with four PCIe slots all with double-spacing - such an i7
board does not exist.
I wish people would read the full article and background info
And btw, four GTX295s would not triple the performance. It
would be double at best. Check toms' specs on the various
dual-GPU boards - no way is a single speed-reduced GTX280
core 3X faster than a single 9800 core. If it's the number
of SPs that matters most, then the speed increase would be
a tad under 2X. However, heat is a problem for a build like
this, as is driver/BIOS support to get all four cards
recognised. The GTX295 is so new (even out yet?) I'd be
surprised if any mbd could utilise four of them atm.
Joost told me they wanted to get the system up and running
quickly. Wouldn't surprise if they bought the same cards
again for any 2nd system since they know it will work ok.