Almost exactly a year ago, SGI rolled out the 64-way Altix 3700 HPC server that employed Intel’s 900MHz/1.5MB L3 cache or 1GHz/3MB L3 cache McKinley Itanium 2 processors. SGI also debuted a desk side variant called the Altix 3300 that scaled from four to twelve of the 900MHz McKinleys. Last July, when the 1.5MHz/6MB L3 cache Madison Itanium 2 processors were launched by Intel, they could be immediately plugged into the Altix 3000 line, yielding about 50% more performance.
Both the Altix HPC servers, which are based on the 64-bit Itanium processors and run Linux, and the Origin HPC servers, which are based on SGI’s own 64-bit MIPS RISC processors and its own Irix Unix variant, have SGI’s NUMAFlex clustering technology at the very heart of their systems. With the NUMAFlex cache-coherent, non-uniform memory architecture, each processor runs its own instance of an operating system (in this case, Linux or Irix), but like processors in a symmetric multiprocessing (SMP) cluster (a clustering method that is common in generic servers and workstations today), all of the processors in a NUMAFlex cluster can access the same-shared pool of memory. Any time processors and applications have a single main memory space to play with; it simplifies programming and allows bigger programs and more programs to run more efficiently on a machine than is possible in a loosely coupled machine.
The new Altix 350s bear some resemblance to the Origin 350 midrange boxes that SGI launched in April 2003. Both use the third generation NUMAFlex architecture, and are based on rack-mounted servers that are denser than their bigger brethren. Chip for chip, the performance of the Altix 350s is probably going to be better than the Origin 350s for certain workloads, given that the Origin 350s use 600MHz or 700MHz R16000 processors. However, the Origin 350s can scale to 32 processors in a single memory space, compared to 16 processors with the Altix 350. That’s because the Origin 350s are based on four-way cell boards instead of the two-way cell boards used in the Altix 350s.
Fenselau says that over $2bn of the $2.6bn annual midrange HPC server market is comprised of clustered Unix SMP servers that can be replaced by the Altix 350 configurations. This is what SGI is gunning for replacing Unix machines with these Linux boxes, even if it means replacing its own Origin boxes. He says that the Altix 350s have about 50% lower costs and about two to three times better price/performance than the Unix servers that IBM Corp, Sun Microsystems Inc, and Hewlett-Packard Co ship into the HPC midrange. We hope these numbers will not only raise eyebrows, says Fenselau, but will compel customer to consider Altix and Linux instead of Unix for HPC workloads.
Interestingly, Fenselau says that the typical HPC site administrator has about $25,000 a quarter in discretionary spending, and it is no coincidence that the cost of a four processor Altix 350 node is under that limit. In the course of a year’s time, an HPC site could have a fairly powerful 16-processor Altix 350 installed and not have to go through budgetary nightmares.
SGI will roll out the next generation of its NUMAFlex clustering in the second half of 2004, presumably for both Origin-MIPS-Irix and Altix-Itanium-Linux machines. Exactly what SGI has in store for the fourth iteration of NUMAFlex is unclear, but lower latency, higher bandwidth, and more memory scalability seem likely.
This article is based on material originally produced by ComputerWire.
