AMD's new Bulldozer architecture is a major change from its previous Phenom and Phenom II processor technology, as it introduces us to an eight-core processor. That's eight hardware cores, rather than four cores using Hyper-Threading - with the release of its first Bulldozer chip, the FX-8150, AMD genuinely is breaking new ground.

It may sound unlikely, but it's actually AMD that has a track record of introducing innovative new features and technology, while giant rival Intel's expertise lies in the fabrication process, production, marketing and sales.

AMD Opteron moved the memory controller from the chipset to the processor and also introduced native support for 64-bit x86 software. Phenom arrived in December 2007 and introduced a genuine quad-core processor rather than Intel's two-dual-cores-on-the-same-socket-fudge, Pentium D.

With Bulldozer we have eight cores on the same AM3+ processor socket. This socket is backwards-compatible with Phenom II, and is combined with the AMD 9 series of chipsets that was introduced in June 2011. If you need a clue that Bulldozer arrived later than AMD intended, we'd point you to the fact that you could buy an AM3+ motherboard months before the new processor was available.

So what is Bulldozer?
There are three versions of Bulldozer. The first is code-named 'Zambezi', the desktop processor, which has a single HT (Hyper Transport) link. Then we have two server chips: 'Valencia' can be used in single- or dual-processor mode; while 'Interlagos' is essentially two Valencia cores on the same socket, and can be used with 1-4 socket server motherboards.

For the purposes of this review, we'll be looking exclusively at the version of Bulldozer in the desktop Zambezi chips.

Bulldozer uses a 32nm fabrication process, and this appears to be the source of at least some of the delays to this new processor. The original plan was to debut Bulldozer using AMD's tried-and-tested 45nm process; however, it seems that these processors - code-named 'Shrike' - would have been too large, hot, juicy and expensive, so they were scrapped and AMD made the leap to 32nm.

Bulldozer's design is unusual, in that it uses a series of modules, each with two processor cores. Each module carries front-end components such as integer pipelines and L1 cache that are shared by the two local cores. The floating point pipelines and L2 cache are available to all the cores in the processor. There is 2MB of L2 cache for each module and 8MB of L3 for the processor as a whole.

The memory controller has been improved to support dual-channel DDR3-1866MHz.

AMD hasn't included a graphics core in Bulldozer, it rationale being that the feature is reserved for the low-end Fusion APU, and has no part in a high-end performance part.

Turbo Core and Max Turbo speed boosts
AMD has taken a bold approach with regard to the TDP (Thermal Design Power), clock rating and power consumption of each model of Bulldozer. For starters, we have the base clock speed with a 300MHz Turbo Core boost when the processor is under load. If the cores remain fully loaded there is an extra spurt of speed called Max Turbo that adds another 300MHz, provided the processor remains within its thermal limits.

Company: AMD

Website: http://www.amd.com/

Tags: eight-core core i5 amd bulldozer processor 3.6ghz chip intel