IDF: Dynamic overclocking for Core i7

 

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Posted on 20 Aug 2008 at 00:32

Intel has released more details of its Core i7 processor, also known by the codename Nehalem.

Senior Vice President Pat Gelsinger showed pre-production silicon at the Intel Developer Forum and confirmed that the i7 is on course for a launch before the end of 2008, with mobile versions due next year in dual and quad-core designs.

Cutting power, raising performance

The crowd of over 2,000 attendees was also given new information about the i7's power management subsystem.

The processor uses a more sophisticated version of the clock gating system used in current Intel processors. In Core 2 processors, portions of the CPU can be disabled when they're not needed, but "leakage power" continues to flow through them.

The new Nehalem implementation uses switchable resistors to prevent power flowing down disabled pathways, further reducing the CPU's power consumption.

The new CPUs also offer a novel feature called "Turbo Mode", which kicks in when the processing load is unevenly distributed between cores. In Turbo Mode, voltage is automatically diverted from less active cores to the busy one, which is then dynamically overclocked to help them deal with the load.

These features will be handled by a brand new on-die power control unit comprising over a million transistors.

Author: Darien Graham-Smith in San Francisco