Intel's first dual-core desktop processors are ready to ship, and our tests show they'll deliver some real benefit when you run software on them that's designed to take advantage of the two cores, or when you're performing multiple tasks simultaneously – for instance, running a virus check while surfing the Web.

As the name implies, dual-core processors incorporate two physical processors and two L2 memory caches into one piece of silicon. Intel's first dual-core chip, the 3.2GHz Pentium 4 Extreme Edition 840 (which carries 1MB of L2 cache per core), goes one step further by including Intel's Hyper-Threading technology in each core, which theoretically brings you a "virtual" second processor per core.

Intel's chips are part of a wave of dual-core processing. AMD has already released its dual-core Opteron chips for workstations and servers, and its dual-core Athlon desktop CPUs are due within a few months. Unlike Intel's dual-core chips, the new AMD dual-core processors will not require new chip sets or motherboards, just a BIOS upgrade.

We tested a preproduction reference system from Intel with engineering samples of the P4 EE 840 and the new 955X Express chip set, 1GB of DDR2-667 memory and a Sapphire Radeon 850XT graphics card. The system ran Windows XP Professional.

The dual-core unit showed a slight improvement overall on WorldBench 5 versus the same system equipped with a 3.2GHz P4 (both with Hyper-Threading on). But the new system truly showed its mettle in certain portions of WorldBench 5 – specifically our multitasking test and our media tests with Roxio VideoWave Movie Creator and Windows Media Encoder.

Both applications are multithreaded, which means they can recognise and use the two cores as if they were two separate processors. On the multitasking test, the dual-core CPU produced its best result: It took just 9 minutes, 50 seconds to open numerous Web pages while converting video and music files to Windows Media format.

The dual-core PC also performed well in the Windows Media Encoder test, in which four WAV files and one AVI file are converted to Windows Media format: It shaved 49 seconds off the single-core 3.2GHz P4's time of 6 minutes 29 seconds.

In the VideoWave test, in which several AVI files are edited and converted to different video formats, the dual-core PC was 26 seconds faster than the 3.2-GHz P4 configuration (which took exactly 5 minutes).
Interestingly, we found that the dual-core unit performed better on the multithreaded applications with Hyper-Threading turned off than with the technology enabled.

Don't expect dual-core to be the top performer today for games and other demanding single-threaded applications, says Kevin Krewell, editor in chief of Microprocessor Report. But that will change as applications are rewritten. For example, by year's end, Unreal Tournament should have released a new game engine that takes advantage of dual-core processing, Krewell says.