Brand new chip. Same old problem.

After spending some face time with Intel's Core 2 Duo processor, we couldn't have come away more impressed. Core 2 Duo slapped the opposition around in every way that matters, including performance, operating temperatures and even pricing.

But that was the sensible money members of Intel's new desktop CPU family. Now the chip giant has wheeled out the near-£800 flagship of the Core 2 range - the Core 2 Extreme Edition X6800. And like almost every other range-topping CPU, the X6800 represents naff value for money.

Fundamentally, it's the same chip as the much cheaper E6700 model which performed so well in our original benchmarks. So, it's packed with a virtually identical set of Athlon 64- bashing features, including a dual-core architecture, topped with 4MB of shared L2 cache, a four issue-wide instruction core and massively enhanced SSE instruction handling.

Indeed, it differs only in offering an overclocking-friendly unlocked CPU multiplier and a bump in clockspeed from the E6700's 2.66GHz frequency to 2.93GHz. Not much, considering the £350 price premium Intel is charging.

Making matters worse, Intel has also announced a Xeon-branded workstation variant of this chip which sports a 3GHz clockspeed and 1.33GHz system bus frequency (the X6800 runs the same 1,066MHz bus as all other non-Extreme Edition Core 2 desktop chips). And all for around £75 less than the X6800.

But if our review sample is anything to go by, the ultimate insult is its overclocking potential. 3.3GHz was the most we could squeeze out using a standard air cooler and voltages. Our 2.66GHz E6700 managed 3.2GHz using the same setup.

The X6800 is by far the fastest desktop processor ever made. It absolutely flattens AMD's Athlon 64 FX- 62, while remaining cool, calm and collected throughout.

The Core 2 Duo range should be at the top of your shopping list if you are considering an upgrade. But pretty please, steer clear of this Extreme Edition, it's just not worthy of your hard-earned. Jeremy Laird