[Beowulf] Intel shows 48-core 'datacentre on a chip'

[Eugen Leitl]

http://news.zdnet.co.uk/hardware/0,1000000091,39918721,00.htm

Intel shows 48-core 'datacentre on a chip'

* Tags: * Manycore, * Cloud, * Operating System, * Processor

Rupert Goodwins ZDNet UK

Published: 02 Dec 2009 18:00 GMT

Intel has announced the Single-chip Cloud Computer (SCC), an experimental
48-core processor designed to encourage research and development in massively
parallel computation.

Measuring 567 square millimetres — about the size of a postage stamp — the
SCC combines 24 dual-core processing elements, each with its own router, four
DDR3 memory controllers capable of handling up to 8GB apiece, and a very fast
on-chip network.

Although no performance, speed or total bandwidth figures were revealed, the
chip has 1.3 billion transistors, consumes up to 125 watts in operation, and
will become available to researchers around the world on a standard-sized
motherboard in the first half of 2010. Intel said it expects to sign up
dozens of partners within six months, with more to come over time.

"This is the prototype of the microprocessor of the future", Joseph Schütz,
director of microprocessor and programming research at Intel Labs, said on
Tuesday. The announcement took place at the company's R&D centre in
Braunschweig, Germany, at the first of three SCC launch events around the
world. "Before, if you needed to design software for this level of computing,
you needed your own datacentre. Now, you just need your own chip," said
Schütz.

The SCC, previously code-named Rock Creek, is fabricated in 45nm technology.
The on-chip network is configured as a 6x4 node, two-dimensional mesh. It has
a bandwidth of 256GBps, and each core can run its own independent software as
a fully functional IA-32 processor.

Memory, 384KB of it, is shared between all cores, primarily to speed message
passing, while power management can independently control eight
variable-voltage and 28 variable-frequency areas of the chip. This controls
power consumption, setting it between 25 and 125 watts.  Intel SCC
 
Intel's Single-chip Cloud Computer: 24 dual-core tiles on a 567mm2 die

"We called it the Single-chip Cloud Computer, but it was very difficult to
know how to name it", said Schütz. "You can easily envision many more cores,
just as you could add more servers to a real datacentre. We could build
relatively small systems with hundreds or thousands of cores."

Unlike other manycore systems, the SCC does not maintain data integrity
through cache coherency, where special circuitry keeps multiple caches in
sync across cores.

"Cache coherency consumes a lot of power but isn't that useful," said Schütz.
"You're tempted to do it because you're on one die, but as soon as you go
off-die, it doesn't work. This is a slice of the future in silicon, and we're
giving to people to play with."

Microsoft, a partner in the SCC project, has built support into its developer
toolchain, according to Schütz.

Professor Timothy Roscoe of ETH Zurich, who is developing the experimental
Barrelfish operating system also in conjunction with Microsoft, told ZDNet UK
that the SCC was a particularly good fit for his work.

"Our multikernel architecture has many independent processors with different
attributes, but sharing the same state", he said, "and the SCC looks a dream
platform for testing many of our ideas".

Intel said it will publish full details of the SCC at the International
Solid-State Circuits Conference in San Francisco on 8 February, 2010.