NEC Calls Dibs on Breaking Linux Eight-Processor Limit
Credit Where Credit is Due

Brian Proffitt
Thursday, January 9, 2003 10:50:35 AM
The Open Source community is rarely one of huge technical leaps. Much
of the work that comes out of open-source software projects is
incrementatal, freely building on the work that others have done in
the past--a lesson that could easily be re-learned this week.
For instance, it was clearly evident in the announcement made by Apple
Computers Tuesday about their new default browser, Safari. From the
outset the public knew that new application was based on the
open-source KHTML and KJM libraries.
This lesson also applied to another big announcement this week: the
release of SGI's supercomputer Altix 3000 line. Though, unfortunately,
the lesson was not as clear.
A major slant to the announcement was the fact that that the so-called
eight-processor limit for Linux had been passed. But what various
media outlets, including LinuxPlanet, forgot to mention was that this
limit had already been passed by another company last Fall, thanks in
large part to work performed in the Open Source community.
Japanese computer maker NEC had released a high-end Linux server line,
the Express1000, as early as last November. The Express1000 also
featured 64-bit Itanium 2 processors and started on the low end of the
line with eight-processor, 8-GB memory machines--ramping up to
32-processor, 32-GB servers.
According to NEC's Director of 64-bit Systems David McAllister, the
supposed eight-processor limit was passed when NEC released their
product late last year. The technology that SGI used, he said, was a
direct result of work done by NEC and other companies through OSDL and
the Atlas Project, which is now a part of the Linux on Large Systems
(LoLS) Foundry.
"There's a caveat in the Open Source world that you give credit where
credit is due," McAllister said. Much of the work that SGI capitalized
upon came from the LoLS Project, particularly the NUMA (Non-Uniform
Memory Access) technology, which SGI and NEC both use.
NUMA is a parallel processing architecture used in multi-processor
systems that lets each processor to have its own memory yet also draw
from the memory of other processors if needed. It is the basis for the
ccNUMA architecture that NEC uses, and the NUMAlink architecture used
by SGI.
McAllister explained that while NUMA is key to making multi-processor
machines work, "Linux doesn't understand NUMA, so we have to change
it." This is some of the work that NEC and other companies have been
doing all along.
SGI did not completely forget the roots of this technology. Though no
specific open-source projects were cited in any of the three related
press releases made on Altix 3000 Tuesday, SGI Project Manager Jason
Pettit did emphasize in his earlier interview with LinuxPlanet that
much of the work was done in conjunction and cooperation with standing
open-source projects, such as the LoLS project, the Linux Scalability
Project, and the work done by David Mosberger to port Linux over to
the IA-64 platform.
It should be noted that in none of the information from or
conversations with SGI was a claim made that they were the first to
break the eight-processor limit. However, emphasis was made on the
fact that SGI had moved beyond eight-processor limits and that SGI had
indeed been the first to reach 64-processor status.
According to Ginny Babbitt, the media contact for SGI, the emphasis
was made on passing the limitation because "so much of the horizontal
press was claiming that Linux could never go past eight."
Another reason NEC's product was not mentioned according to SGI's
Addison Snell, Marketing Manager of High Performance Computing, was
because SGI did not consider them to be a direct competitor, and that
comparing one's product to a non-competitior "would be rude."
Based on the sectors that NEC is targeting, this appears correct. NEC
is marketing their product line to financial, transactional commerce,
and research customers, while SGI is targeting life and physical
sciences; media; defense and government; energy; and manufacturing.
Thoughout the clarification of who got past the eight-processor limit
first was important to him, McAllister repeatedly emphasized that much
of the real work done on this technology came from the efforts of the
Open Source community and that the real credit should go there.
Snell responded to McAllister's comments by repeating the project ties
SGI has had with open source.
"We're very proud of our relationship with the Open Source community,"
Snell said.