Canada's fastest computer simulates galaxies, black holes (Forwarded)

Department of Public Affairs
University of Toronto
Toronto, Canada

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July 21, 2003

Canada's fastest computer simulates galaxies, black holes

System performing leading-edge astrophysical research

By Nicolle Wahl

A $900,000 supercomputer at the University of Toronto -- the fastest computer in
Canada -- is heating up astrophysics research in this country and burning its
way up the list of the world's fastest computers.

The new computer, part of the Department of Astronomy and Astrophysics and the
Canadian Institute for Theoretical Astrophysics (CITA), was ranked as the
fastest computer in Canada and the 39th fastest in the world in the latest list
from www.top500.org, compiled by the Universities of Mannheim and Tennessee and
the National Energy Research Scientific Computing Center at Lawrence Berkeley
National Laboratory.

"An essential element of modern astrophysics is the ability to carry out
large-scale simulations of the cosmos, to complement the amazing observations
being undertaken," said Professor Peter Martin, chair of astronomy and
astrophysics and a CITA investigator. "With the simulations possible on this
computer, we have in effect a laboratory where we can test our understanding of
astronomical phenomena ranging from the development of structure in the universe
over 14 billion years to the development of new planets in star-forming systems
today."

When the computer, created by the HPC division of Mynix Technology of Montreal
(now a part of Ciara Technologies), starts its calculations, the 512 individual
central processing units can heat up to 65 C, requiring extra ventilation and
air-conditioning to keep the unit functioning.

But with that heat comes the capability of performing more than one trillion
calculations per second, opening the door to more complex and comprehensive
simulations of the universe. It is the only Canadian machine to break the
Teraflop barrier -- one trillion calculations per second -- and it's the fastest
computer in the world devoted to a wide spectrum of astrophysics research.

"This new computer lets us solve a variety of problems with better resolution
than can be achieved with any other supercomputer in Canada," said Chris Loken,
CITA's computing facility manager. "Astrophysics is a science that needs a lot
of computer horsepower and memory and that's what this machine can provide. The
simulations are also enabled by in-house development of sophisticated parallel
numerical codes that fully exploit the computer's capabilities."

The machine, nicknamed McKenzie (after the McKenzie Brothers comedy sketch on
SCTV), with 268 gigabytes of memory and 40 terabytes of disk space, consists of
two master nodes (Bob and Doug), 256 compute nodes, and eight development nodes.
All of these are networked together using a novel gigabit networking scheme that
was developed and implemented at CITA. Essentially, the two gigabit Ethernet
ports on each node are used to create a "mesh" that connects every machine
directly to another machine and to one of 17 inexpensive gigabit switches. It
took four people about two days and two kilometres of cable to connect this
network. The unique CITA design drives down the networking cost in the computer
by at least a factor of five and the innovative system has attracted industry
attention.

Professor John Dubinski has used the new computer to examine both the formation
of cosmological structure and the collisions of galaxies by simulating the
gravitational interaction of hundreds of millions of particles representing
stars and the mysterious dark matter. The anticipated collision of the Milky Way
Galaxy with our neighbouring Andromeda galaxy -- an event predicted to take
place in three billion years time -- has been modeled at unprecedented resolution.

New simulations on the formation of supermassive black holes, again with the
highest resolution to date, have been carried out by his colleagues Professors
Ue-Li Pen and Chris Matzner. They have already uncovered clues which may explain
the mystery of why the black hole at the center of our galaxy is so much fainter
than had been expected theoretically.

The team has even grander plans for the future. "In astrophysics at the
University of Toronto we have continually exploited the latest computing
technology to meet our requirements, always within a modest budget," Martin
said. "This is a highly competitive science and to maintain our lead we are
planning a computer some ten times more powerful."

Funding for the computer was provided by the Canada Foundation for Innovation
and the Ontario Innovation Trust.


View galaxy collision simulations:
http://www.cita.utoronto.ca/%7Edubinski/nbody

[Nicolle Wahl is a news services officer with the department of public affairs.]

RELATED STORIES:

* Canada's fastest computer devoted to astrophysics (Feb. 10, 2003)
http://www.newsandevents.utoronto.ca/bin4/030210f.asp

IMAGE CAPTIONS:

[Image 1:
http://www.newsandevents.utoronto.ca...5/mckenzie.jpg (19KB)]
The PowerRack-HX Cluster -- L-R: Adrian Martin (3rd year mechanical and
industrial engineering student), Chris Loken, Ue-Li Pen, Taylor Martin (1st year
mechanical and industrial engineering student)

[Image 2:
http://www.newsandevents.utoronto.ca...gasblkhole.jpg (19KB)]
Gas accreting into a black hole. Image: Ue-Li Pen, Dept. of Astronomy and
Astrophysics/CITA