Comparing the Phenom II X4 series to the latest Intel Core i7 processors is not completely fair, as they are intended to serve two different markets, at least for now. At $290 the Core i7 920 is slowly closing the gap, though with the current pricing of Intel X58 motherboards and triple-channel DDR3 memory kits, the main target for the Phenom II X4 is still the Intel Core 2 Quad.
The Phenom II X4 955 was for the most part faster than the Core 2 Quad Q9650 and best of all it's substantially cheaper at $245. The subtotal cost of a Phenom II X4 955 system using a basic setup (Phenom II X4 955 = $245, 4GB DDR2 = $40, and AM2+ motherboard = $100) could set you back less than $400. Building a Core i7 920 system will cost at the very least $500 (Core i7 920 = $245, 3GB DDR3 = $60, and LGA1366 motherboard $200). That said, for the extra $100 or so, the Core i7 920 processor was considerably faster in a number of real-world tests.
While it might make more sense to go for the Core i7 920 option if you are building from the ground up, the Phenom II X4 955 offers existing AMD users with an appealing upgrade path. Those already using an AM2+ system with an older Athlon64 X2 or Phenom processor can breathe new life into their system for $245 which doesn't sound like a bad deal.
Back when we tested the original Phenom II X4 940 and 920 processors, we were impressed by the gaming performance improvements that these offered over the older Phenom X4 9950. The Phenom II X4 955 was very similar in this respect, although gaming benchmarks can be somewhat misleading due to GPU limitations, the Phenom II X4 955 is a very competitive gaming processor.
Although we had limited time to test the overclocking capabilities of the Phenom II X4 955 Black Edition processor, reaching a stable 3.70GHz overclock was done in no time thanks to the unlocked multiplier. This adds some weight to the processor, especially considering that Core 2 processors are overclocking friendly components. Given how quickly we achieved this overclock, we believe that through further tweaking and possibly better cooling, many users will exceed our mark.
Looking at the little impact DDR3 had on the Phenom II X4 955, we were not surprised to find this. By using this new processor on the older AM2+ platform with DDR2 memory, users are sacrificing very little, and in terms of value this is a far smarter option.
Overall we are pleased with what AMD has accomplished with the Phenom II X4 processor series, and the Phenom II X4 955 is a worthy addition to their quad-core family. While AMD may not be setting any performance records with this new processor, they are applying even more pressure to Intels mainstream processors, and ultimately this is good news for the consumer.