This year was kick started with a review of the first Phenom II X4 processors, being the 940 and 920 models, based on the “Deneb” architecture. When compared to the existing Phenom X4 processors, these second generation parts boasted a few significant changes, most notably the core operating frequency and L3 cache had both been significantly increased.

The flagship processor, being the Phenom II X4 940, operated at 3.0GHz, while the L3 cache had been boosted from 2MB to 6MB. Another important change saw the Phenom II X4 go from a 65nm design to a 45nm design process, reducing the die size, improving thermal output, and drastically reducing power consumption.

However, for the most part the architecture of the Phenom II X4 was much the same as the original, with a few tweaks here and there. The new Phenom II X4 955 processor offers few improvements over the 940 model, with the most significant being its 3.20GHz operating frequency, giving it a 6.5% clock speed advantage. The L2 and L3 cache capacities remain unchanged on this new model, while the HyperTransport frequency does receive a small boost.

The key feature is the AM3 platform support, making the Phenom II X4 955 one of AMD’s most flexible processors yet. While this new processor is designed to work with the new AM3 platform, it is also 100% backwards compatible with the AM2+ platform. This means installing the new Phenom II X4 955 processor on any AM2+ motherboard is possible, while doing so users will sacrifice very little performance and in most cases none at all.

The Phenom processors have always been about value, and since being introduced they have been the cheapest way for users to get their hands on quad-core technology. The Phenom II X4 940 for example debuted at just $270 US, while today it can be had for the bargain basement price of $190 US. In terms of performance we found that it closely matched the Core 2 Quad Q9650, which was considerably more expensive then at $540 US, and even today it's still fetching around $330 US.

At the time the Phenom II X4 940 was certainly a remarkable thing at $270 US, so needless to say we are shocked by the fact that AMD are telling us that the Phenom II X4 955 will start at just $245 US. This is amazing, though with the 940 now priced at less than $200 US, the suggested price tag for the 955 does make sense. Already the Phenom II X4 955 is shaping up to be the ultimate upgrade solution for AM2+ users that have been holding out.

Given that just a few months ago we took an in-depth look at the new Phenom II X4 series, there is little point going over all that information again as little has changed. The key focus of the Phenom II X4 955 is its ability to work with either DDR2 or DDR3 memory, and therefore we have tested this processor with both memory types. It is also worth noting that although the AM3 platform is new, it fails to deliver any new chipsets and therefore the AMD 790FX was used to test both configurations.