Intel's new dual core Pentium processor (codenamed Smithfield), which has a slower clock-speed than the current batch of single core CPUs on the market, has proven itself to be twice as fast in some tests carried out by PCW's labs.

The 3.2GHz Pentium Extreme Edition 840 processor (Intel has dropped the Pentium 4 name for this new model) is Intel's first dual-core CPU. In effect you get two Prescott P4 CPUs each with Hyper Threading (HT) in a single package, which can help boost PC performance when running suitable multithreaded applications - to Windows, the 840 appears as four virtual CPUs.

Our tests show that in some tasks the twin HT cores can outperform a faster single core HT processor.

The new processor was outperformed in some tasks by Intel's older, faster CPUs though, and in several tests did not provide exceptional performance benefits. But this was because the tests did not use the CPU's two cores and so the results reflected the fact that the Pentium 840 has a slower 3.2GHz clock speed than the old P4 Extreme Edition.

The independent tests, the results of which can be found on the The Test Bed - PCW's labs blog - found that when rendering images using all four virtual CPUs it was 54 per cent faster than the 3.7GHz Pentium 4 Extreme Edition with its two virtual CPUs.

It performed well in multithreaded tests, but in single-threaded tests its slower clock speed meant it was outperformed by the older Extreme Edition CPU.

Both AMD and Intel are releasing dual-core processors. Currently there are few applications on the market which can take full advantage of the new CPUs by sharing task between both cores (multithreading). But it does mean that when several software programs are running these can be shared across the cores, boosting a PC?s performance and responsiveness.

In future, both Intel and AMD expect all their processors to contain two or even more cores. Shipping dates and pricing for the Pentium 840 have not yet been announced.