AMD plans to underclock its Phenom II X6 chips

Cutting performance to boost performance...

 AMD intends to implement "Turbo Core" technology in its upcoming Phenom II X6 chips, which will underclock three out of six cores and overclock the other three depending on system load levels.

The details revealed on a number of websites show that AMD's upcoming six-core Phenom II processors will be clocked competitively against Chipzilla's offerings and feature auto-overclocking technology. AMD's Turbo Core technology will take a slightly different approach than Intel's Turbo Boost first seen in its Core i7 Nehalem chips over a year ago.

Unlike Intel's part-time overclocking technology, which shifts core multipliers up a gear or three when the going gets tough, AMD's competing Turbo Core will overclock one half of the cores and underlock the other half. The interesting bit of all this is that the Phenom II X6 will perform this clock shifting when there's not much going on, so you could end up with a overclocked three-core CPU chip.

According to the figures, the overclock is pretty aggressive, showing a 400MHz to 500MHz jump in clock speed depending on the part. Because the chips will underclock three cores down to a leisurely 800MHz, those cores running at close to a 20 per cent overclock will be able to stay within the thermal design power envelope of 95W or 125W.

Slides published by The Boy Wonder show that Turbo Core will not require any software to be installed and that all Socket AM3 motherboards will support this feature, although possibly some will require a BIOS update. The slides also show that only the active cores will be clock-boosted, up to a maximum of three.

Seemingly AMD believes that having fewer, faster cores is a better use of power. That might well work out in its favour in certain benchmarks that don't scale too well with the number of cores.

AMD's Phenom II X6 chips are slated to appear sometime within the next three months and should provide a much needed foil for the six-core Nehalem chips that Intel recently launched. The content of Phenom II X6 reviews might have to include performance figures for both three and six cores in order to explain the likely performance range within the same chip.