Dr. Dobb's | World's Fastest Processor? For Now, Anyway

World's Fastest Processor? For Now, Anyway

A multi-core processor that increases the speed, while keeping energy consumption the same

May 21, 2007
URL:http://www.drdobbs.com/parallel/worlds-fastest-processor-for-now-anyway/199700333

IBM has launched what it claims is the fastest microprocessor ever built -- the 4.7-GHz, dual-core POWER6. According to IBM, the processor doubles the speed of the previous generation POWER5 which, in a new kind of benchmark, delivers enough bandwidth to download the entire iTunes catalog in 60 seconds. That tops out at 300 gigabytes per second -- 30 times faster than HP's Itanium, according to IBM. The processor also uses nearly the same amount of electricity as the POWER5.

The POWER6 supposedly 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 advantage to enterprises running complex tax, financial, and ERP programs, among others.

The POWER6 processor is built using IBM's state-of-the-art 65 nanometer process technology. Coming at a time when some experts have predicted an end to Moore's Law, which holds that processor speed doubles every 18 months, the IBM processor is driven by a number of technical advances scored during the five-year research and development effort to develop the POWER6 chip. These include:

A dramatic improvement in the way instructions are executed inside the chip. IBM scientists increased chip performance by keeping static the number of pipeline stages -- the chunks of operations that must be completed in a single cycle of clock time -- but making each stage faster, removing unnecessary work and doing more in parallel. As a result, execution time is cut in half or energy consumption is reduced.
Separating 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.
Voltage/frequency "slewing," enabling the chip to lower electricity consumption by up to 50 percent, with minimal performance impact.
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. The chip has configurable bandwidth, enabling customers to choose maximum performance or minimal cost.

The POWER6 chip includes additional techniques to conserve power and reduce heat generated by POWER6 processor-based servers. 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.

Power saving is also realized when the memory is not fully utilized, as power to parts of the memory not being utilized is 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.

IBM plans to introduce the POWER6 chip throughout the System p and System i server lines.