Intel has revised its four-core desktop processors, the 2.4GHz Core 2 Quad Q6600 and the 2.93GHz Core 2 Extreme QX6800, the chip giant warned its customers yesterday. The move had been expected.

Both processors will now be available in new versions - known as 'steppings' in the chip business - both called 'G-0'. Past quad-cores were at stepping 'B-3'. The new cores add no new features, Intel said, instead focusing on the processors' thermal characteristics.

The "Maximum allowed Case Temperature" (MCT) for the Core 2 Extreme has been increased by 9.7°C, while the Core 2 Quad's MCT is now up 11°C. That means both can run hotter, handy for folk who want to try increasing the chips' clock speeds, or spin down their computers' cooling fans to make them quieter.

The Core 2 Quad now consumes up to 95W, down from 105W.