VirtuOS and virtual SMP technology
Large servers use a design called symmetrical multiprocessing, or SMP, to link their chips together so a single operating system can span the chips. VirtuOS uses its own proprietary software and high-speed InfiniBand networking links from TopSpin Communications to create what Davis called "virtual SMP."
Others have dabbled with the idea before, including, in 2001, Dell, which scrapped its SMP-over-InfiniBand project before it ever came to fruition.
Davis said the virtual SMP technology is limited not by VirtuOS but by how big a server Linux can use today, about 16 processors.
If the VirtuOS software works as advertised, it could offer compelling price advantages. For example, a setup with eight reasonably powerful IBM x336 servers with dual Xeon processors costs roughly $32,000, whereas, according to IBM, buying that many processors in a single SMP system, a 16-processor x445, costs about $102,000.
But InfiniBand simply isn't fast enough to reproduce the performance of the high-speed interconnects that link processors and memory in a multiprocessor server, Illuminata analyst Jonathan Eunice said.
The delay, or latency, between when a processor tries to read data from memory and when that memory actually arrives is about 200 nanoseconds, or billionths of a second. InfiniBand latencies are about 8,000 nanoseconds, he said.