AMD has finally lifted the lid on its long awaited Phenom quad-core PC processor. It has also unveiled its new Spider PC platform which supports up to four graphics cards running in parallel.

Two Phenom processor models are available from today, the 2.2GHz Phenom 9500 and 2.3GHz Phenom 9600. AMD's main rival Intel has been shipping 3GHz quad-core processors for approximately six months.

However, AMD has emphasised that the new chip is just one part of its new Spider PC platform. Spider comprises the Phenom CPU, the new 7 Series motherboard chipset and the Radeon HD 3800 Series 3D chip ( announced last week) from AMD's graphics subsidiary, ATI.

According to AMD, the whole of Spider is greater than the sum of its parts. Thanks to the purchase of Canadian graphics outfit ATI last year, AMD says it is now in a unique position to supply a full suite of high performance parts - chipset, processor and graphics. This, AMD claims, gives it an unparalleled ability to deliver a highly optimised and stable desktop PC platform.

It's a nice idea, but is it true? We'll post our full reviews of the new Phenom processors, Spider platform and the Radeon HD 3850 GPU elsewhere on Tech.co.uk today. The short version is that the Phenom processor will struggle to be competitive at just 2.3GHz.

Based on Barcelona

Based on the same basic architecture as the Barcelona quad-core server and workstation CPU, Phenom is a true quad-core PC processor built using a single CPU die. Intel's current quads are actually two dual-core dies wired into a single package. However, Phenom is not an all-new design.

Rather, it is a revision of AMD's existing K8 architecture as seen in the Athlon 64 since 2003, albeit with several significant revisions. The most significant tweak is the doubling of floating point unit width to 128-bit.

As for the new 7 Series chipset, it will be available in three trims, the 790 FX, 790 X and plain vanilla 790, catering for the enthusiast, performance and mainstream markets, respectively.

All 7 Series motherbaords will pack the new PCI Express 2.0 interconnect. The doubling of bandwidth to data-hungry peripherals, most significantly graphics cards, is the main benefit.

Significant for CrossFire

It won't make a huge difference for systems with a single video card. But it does become significant in the context of the 790 FX's support for anything up to four ATI graphics cards running in CrossFire multi-GPU mode. AMD claims that quad CrossFire arrangements can deliver up to 3.2x the performance of a single card.

The final major feature for the 7 Series chipset is the new AM2+ CPU socket. Several Phenom features including HyperTransport 3.0 and the split-plane power management require AM2+ for full exposure. However, Phenom is also backwards compatible with existing AM2 motherboards.

Several motherboards based on the 7 Series chipset are already on sale at the usual online retailing suspects. AMD says Phenom processors are shipping to retailers even as we type.

UK pricing for the new Phenom processors is expected to be in the £135 to £160 range.