AMD FX-8150 computer processor

In comparison to its graphics division, AMD's processor division has had a tough time recently, with nothing much to shout about. Now it's the processor department's turn in the sun with the arrival of the long awaited Bulldozer CPU architecture for the AM3+ socket.

The 32nm-process Bulldozer architecture is all-new, and is AMD's first new architecture from the ground up since the heady days of the first Athlon launch some eight years ago. It's the company's first 32nm desktop part.

Instead of the usual core design AMD has built the architecture for this chip in modular form, each module being in essence a dual-core processor, and each core having its own 128KB of Level 1 cache. The 8MB of Level 2 cache is shared between the cores in the module. There is also 2MB of Level 3 cache for each module.

Being a modular design, the architecture is highly scalable, allowing AMD to produce multi-cored processors just by adding more Bulldozer modules, so in theory it will possible in future for the company to bring out processors with 10 or 12 cored and beyond. The processor supports DDR3 memory speeds up to 1866MHz.

The first of these new CPUs we have seen is the flagship FX-8150 (codename Zambezi), an eight-core chip (AMD claims it's the world's first) with a clock speed of 3.6GHz and a turbo speed that takes it to 4.2GHz. Its multipliers are unlocked, which means there is lots of overclocking potential - we managed to get the review sample up to 4.6GHz with air cooling.

Joining the FX-8150 at launch were the FX-8120 (eight cores, 3.1GHz), FX-6100 (six cores, 3.3GHz) and the FX-4100 (four cores, 3.6GHz) with more to follow. One thing missing from the FX range of chips is integrated graphics.

Performance-wise there's an air of disappointment about the FX-8150: we got the feeling it should have been faster than it actually is. When tested with the X264 HD encoding benchmark it gave a score of 38fps, faster than Intel's i5 2500K but not as much as you might think (the i5 gave 32fps while Intel's top-end i7 2600K made 46fps).

It was the same in Cinebench 11.5's multiple thread test, the FX-8150 just managing to beat the i5 (5.95 compared to 5.87) while the i7 2600K raced ahead with a score of 7.43.

AMD's completely new design shows great promise for the future - all it needs now is for software developers to hurry and design apps to make use out of all those cores. The current price is worrying too, as it's around £30 more expensive than Intel's i5 2500K.