AMD Athlon 64 X2 65nm Brisbane-Core

AMD Athlon 64 X2 65nm "Brisbane" Close Up

When the 90nm Athlon 64 X2 was released, we saw processors with a Maximum Thermal Power rating of 89 watts, with low power flavors later offering 65 and 35 watt Maximum Thermal Power ratings at lower processor speeds.  With a reduced die size from 183mm2 with the "Windsor" core to 126mm2 with the new "Brisbane" core, AMD has taken the low power mantra and made it standard across the board, rather than designating a Low Power-processor and offering it as an additional cost as was done with "Windsor".

When we look at this new line up, there are several changes to consider.  First, when compared to its 90nm brethren, the X2 5000+ remains unchanged with respect to L2 Cache and clockspeed, however, the rest have all shifted to a more consistent L2 complement of 512KB while adding a slight increase in clock speed.

It's clear that with the new 65nm process, AMD is looking to simplify their offerings so that the only thing to consider between the four models listed would be clock speed.  In the case of the 4000+, 4400+ and 4800+, AMD has bumped the clockspeeds up 100MHz with each in to offset the affects of cutting the L2 cache in half.

Like the "Windsor" core, "Brisbane" maintains an approximate Transistor count of 153.8 million.  The Nominal Voltage has reduced, ranging from 1.25-1.35v with "Brisbane" compared to the "Windsor" core's 1.3-1.35v.  One other change is that AMD has introduced a half stepping with the CPU multiplier, allowing for even 100MHz memory frequency steps.

In both cases, the "Windsor" and "Brisbane" based Athlon 64 X2 5000+'s we are using for testing sport the same 512KB of L2 cache per core, support the same instructions and run at the same frequency.  This makes for an excellent apple-to-apples test comparison.