Intel last week introduced the first laptop chips to support its HyperThreading technology, designed to boost performance by making the chip appear to software as two virtual processors.

The move will lead to a new generation of higher performance desktop replacement laptops, offering all the capabilities of a desktop PC in a portable format.

However, the low number of applications written to support multi-threading are likely to limit the performance benefits for many core business processes.

Tests conducted by IT Week show that most desktop software works more slowly with HyperThreading enabled.

The Mobile Pentium 4 with HyperThreading technology is available immediately at speeds of 3.2GHz, 3.06GHz, 2.8GHz and 2.66GHz.

It follows the first Mobile Pentium 4 processors announced in June, which lack HyperThreading, a feature supported in full-blown desktop chips since last year.

The Mobile Pentium 4s are essentially desktop processors with additional power management capabilities such as Intel's SpeedStep technology, Deep Sleep and Deeper Sleep modes.

While this helps to reduce power consumption, the chips will still run hotter and consume more power than processors designed from scratch to be used in laptop computers.

But many buyers seem to prefer the desktop replacement format. According to figures from research company MobileTrax, 44 per cent of laptops purchased by large firms last year fell into the desktop replacement category.

Another 33 per cent were so-called thin and light models, the more portable format targeted by Intel's Pentium M and its Centrino mobile platform.

The Mobile Pentium 4 replaces the Mobile Pentium 4-M, a mobile processor that was seen as suffering from poor performance.

The Mobile Pentium 4s with HyperThreading cost $653 (3.2GHz), $433 (3.06GHz); $294 (2.8GHz) and $234 (2.66GHz).