IBM just launched the dual-core 64-bit POWER6 processor
running at 4.7 GHz, which doubles the speed of the previous generation POWER5
while using nearly the same amount of electricity to run and cool it.
The POWER6 processor is a result of a five-year R&D
period, is composed of 790 million transistors and is built using IBM’s 65nm
process technology. IBM scientists targeted the way instructions are executed
inside the chip to improve performance. For example, in the POWER6, the number
of pipeline stages – the chunks of operations that must be completed in a
single cycle of clock time – are kept static, but each stage is made faster,
removing unnecessary work and doing more in parallel. As a result, execution
time is reduced.
Earlier this year, IBM hinted that its new POWER6 architecture may hit frequencies higher than 5 GHz.
The POWER6 chip has a total cache size of 8 MB per chip –
four times the POWER5 chip – to keep pace with the processor bandwidth. With 300
GB/s on tap, IBM boasts that its processor has so much bandwidth that the
POWER6 chip could download the entire iTunes catalog in about 60 seconds. IBM
believes that it has designed the POWER6 chip with a balanced amount of
bandwidth and processing power.
“Like the victory of IBM’s Deep Blue chess-playing
supercomputer 10 years ago this month, the debut of POWER6 processor-based
systems proves that relentless innovation brings ‘impossible’ goals within
reach,” said Bill Zeitler, senior vice president, IBM Systems and Technology
Group. “The POWER6 processor forges blazing performance and energy conservation
technologies into a single piece of silicon, driving unprecedented business
value for our customers.”
To facilitate the lower energy demands of the new chip, the
POWER6 designers separated circuits that can’t support low voltage operation
onto their own power supply “rails,” allowing IBM to dramatically reduce power
for the rest of the chip. IBM engineers also used a new method of chip design
that enables POWER6 to operate at low voltages, allowing the same chip to be
used in low power blade environments as well as large, high-performance
symmetric multiprocessing machines.
In another design to reduce energy consumption and heat
production, processor clocks can be dynamically turned off when there is no
useful work to be done and turned back on when there are instructions to be executed.
Also, the chip has configurable bandwidth, enabling customers to choose maximum
performance or minimal cost.
Parts of the memory not being utilized are dynamically turned
off and then turned back on when needed. In cases where an over-temperature
condition is detected, the POWER6 chip can reduce the rate of instruction
execution to remain within an acceptable, user-defined temperature envelope.
The chip is fast too, as a server built by IBM using the
POWER6 architecture is the first ever to hold all four major benchmark speed
records for business and technical performance. IBM says that its new 2- to
16-core server is multiple times faster than the HP Superdome or Itanium machines.
The POWER6 chip is also aimed as being a midrange
consolidation machine, containing special hardware and software that allows it
to create many virtual servers on a single box. IBM calculates that 30 SunFire
v890s can be consolidated into a single rack of the new IBM machine, saving
more than $100,000 per year on energy costs.
IBM plans to introduce the POWER6 chip throughout the System
p and System i server lines. The POWER6 chip in the new IBM System p 570 server
is the first UNIX microprocessor able to calculate decimal floating point
arithmetic in hardware. Until now, calculations involving decimal numbers with
floating decimal points were done using software. The built-in decimal floating
point capability gives tremendous advantage to enterprises running complex tax,
financial and ERP programs.