SGI Demos 64-Proc Linux Box
foobar104 writes "Details are scarce, but SGI announced this morning that their prototype Itanium 2 system has demonstrated more than 120 GB/s to and from main memory on the STREAM TRIAD benchmark, which is the fourth best result in the world. For comparison, the Cray C90 sustains 105 GB/s, while an even larger Sun Fire 15K clocks a measly 55 GB/s. The interesting part? The system wasn't running IRIX, SGI's proprietary version of UNIX. It was running Linux. More information on STREAM TRIAD, including results from other systems, is available here. The system, incidentally, was an Origin 3800 straight out of manufacturing equipped with Itanium 2 processor modules. SGI will start selling the systems early next year."
To me, it would seem that the primary purpose of being able to push info that fast to and from memory is useful for very few problems these days. I was under the impression that the majority of "super-computing" problems were of the sort that required lots of calculations, not lots of parsing of information in storage.
Am I wrong about what this benchmark means? Or am I missing something basic?
If we could work together (plus Mr Perens who is currently looking for a good cause to lead) we could take the demo to greater heights.
What is to say that the demo's code isn't buggy and shoddy, holding the power Itanium processors back?
If we realize the vast potential that the Open Source developer community provides then we can tackle such complex tasks as this Itanium performance measurement.
Wearing pants should always be optional.
Anyone have an educated guess of what the actual score would be?
Zero. Origin servers don't have graphics cards. Which means, unfortunately, the Slashdot community is going to have to try to wrap its collective head around a more meaningful measurement of potential performance.
SGI didn't choos to comapre this to a C90, the slashdot submitter did. SGI primarily compared it to the "IBM® eServer p690 and Sun Microsystems Sun Fire"
The part that I really find interesting is that the top three in the list all outperform this by twice as much, the #1 spot being held by a machine that can do over 500GB/sec.
It's still over 12x faster then the quad Itaniums I used to work with, and probably much cheeper then the NEC machines and the Cray...
That said, it's an impressive result. And it's done in an unusual way. SGI has a 1.6GB/s channel running through routers connecting the processors and memory. A computer is made up of multiple rackmount "bricks" connected by cables and routers. The "router" is a 2U rackmount device.
Processors and memory reside in rackmount boxes with 4 CPUs and 8 GB (max) of local memory. These boxes interconnect through a single 1.6GB/s link per box, which, in a big system, goes through several layers of routers. So a memory access to another box is routed through what is essentially a fast LAN. All this is cached, of course.
It's not clear to what extent application programs have to be aware of this. Clearly, if you lay things out in memory badly, with lots of CPUs reading and writing the same memory from all over the memory net, the system will bottleneck. (Everybody reading the same stuff is OK; it's cached. But writes have to propagate back to the home location of the data.)
Since the whole monster crashes all at once, you don't want to build your web server farm this way. It's for applications that really need all that crunch power in one machine.