Intel claims that a dual-core Core 2 Extreme launched today is the world's fastest mobile processor – and that the company is on track to launch a low-drain quad-core for notebooks next year.

It also launched five new desktop processors, including two quad-cores clocking 2.66GHz and 3GHz respectively, and three dual-cores. AMD's first Barcelona quad-cores, due to launch within a few weeks, are reported to clock only a disappointing 2GHz.

AMD has long demonstrated that clock-rates are not a reliable measure of performance but Barcelona had been expected to run faster, giving rise to speculation about production problems. Barcelona is, however, true quad-core as opposed to being two dual-core processors in the same module, like the Intel offerings.

Intel's new Core 2 Extreme X7800 mobile dual-core clocks 2.6 GHz and is said to offer up to 28 per cent better performance than the previous generation. System vendors have also been given more scope to overclock for more performance.

The chip, aimed at hardcore gamers and others who want performance on the move, will cost dealers $851 (£418). It will appear in notebooks within a couple of weeks.

The two new quad cores are the 3GHz Core2 Extreme QX6850, which has a 1.333GHz system bus, and the 2.6GHz Core 2 Quad Q6700 with a 1.066GHz bus. Both have 8Mbyte Level 2 cache and cost respectively $999 (£490) and $530 (£260) in bulk.

The new dual-cores are the Core 2 Duo E6850, the E6750 and the E6550 clock respectively 3GHz, 2.66GHz and 2.33GHz and cost $266(£131), $183(£90) and $163(£80) in bulk. All use a 1.333GHz bus and have 4Mbyte Level 2 cache.