It could be a case of the Emperor's new clothes but the AM2 socket for Athlon 64 isn't just about a change of underwear, it's about DDR2.

You have to admire the size of AMD's kahunas. When it launched the original Athlon 64, it took flak for not supporting DDR2 in its new, integrated memory controller. Traditionally - and on modern Pentium chipsets - motherboards used an extra chip, known as the Northbridge, to manage traffic between the CPU and the memory, the whole governed by the speed of the Front Side Bus.

AMD stuck this interface on the CPU die and replaced the FSB with its proprietary Hypertransport interface; one less bridge chip means lower latencies across the board, with the downside that there's less flexibility in the design to use new technologies, like DDR2.

As history has proved, sticking with DDR1-400 hasn't hurt AMD's performance in the slightest; particularly when it comes to games.

Upper hand

Athlon 64s have pounded Pentium 4s into the ground for some years now, partly due to the more efficient processor design, but also because DDR2 memory simply hasn't delivered on its promises of greater speed thanks to a trade off with higher latencies.

Or that was the case until now. With new 800MHz and 1066MHz modules appearing, the price: performance ratio is starting to shift in favour of DDR2 - largely thanks to investments made by Intel. And for this, AMD shows its thanks by beating its rival to a DDR2-800 capable platform.

The problem is that to introduce a whole new memory technology, AMD has to overhaul its entire processor line with a fresh integrated memory controller - and naturally PCF was the first to receive a sample of these new chips, the top of the range dual core FX62.

Each time AMD has fiddled with the memory controller it has updated the socket to make sure confused consumers don't go and try to force a poor defenceless processor into a socket it's not suppose to mate with.

Pin spike

The move from single channel controllers dual saw the pin counts rise from 745 to 939, and for the new socket - dubbed AM2 - AMD has added one extra pin (purely to differentiate them, we believe).