Intel Sandy Bridge Core i7-2600k

Of all the Intel's new "Sandy Bridge" processors, this model is the most powerful. It runs at 3.4GHz, with a massive 8GB of cache memory built into the chip, and uses four processor cores, each using Intel's Hyperthreading technology to work with two queues of tasks. That means that your computer sees it as not one, two or even four but eight processors.

It even has Intel's own HD graphics system built in, so when connected to a suitable motherboard there's no need for a separate graphics card. We're not so sure that this is so useful on this chip, though, as most people wanting a PC this powerful would be adding a powerful graphics card as well. We tested it using Intel's own DP67BG motherboard and the supplied - and rather large - XTS100H cooler.

The results of our standard video recoding test were impressive, with the i7 chip chewing through the entire video at an average of 169fps (frames per second). That's a huge increase when you compare it to the last generation of Intel desktop chips - the i5 660 ran the same test at 75fps, for example - but not that much higher than its cheaper cousin the i5-2500k, which managed almost 140fps.

This is, however, with the processor only running at its standard 3.4GHz. One of the key advantages of the i7-2600k is that it comes "unlocked" and ready to run at whatever speed you choose. If you're technically adept, and have a good enough cooler to deal with the heat generated, it's possible to slowly crank up the speed - a process called "overclocking".

We were impressed to see that, at its standard settings, the chip didn't rise above 50 degrees during our test, so there's plenty of scope for improvement. It's also reassuring to note that when pushed too hard, with temperatures above 90 degrees, the processor automatically throttled back its own speed to prevent damage.

So is this latest and greatest Intel processor the one to buy? We're not so sure. It's undoubtedly fast, and if you want to hand-build an overclocked computer it would be perfect. For most home PC users, though, we recommend the new i5 range instead - in our tests it gave almost as much power for much less cash, and you should see off-the-shelf PCs using the new i5 chips very soon.