We couldn't go any faster with the older Hammer cores: the Athlon 64 FX-62 topped out at 3.05 GHz.

Compared to Intel's newcomer Core 2 Extreme, the overclocking potential of the Athlon 64 FX-62, which runs at a stock speed of 2.8 GHz, is pretty narrow. We couldn't achieve stable operation at more than 9 percent faster than stock speed, whether we used air or water cooling. This resulted in a top speed of 3.05 GHz. As soon as the clock multiplier was increased by 1, the motherboard won't start up any more. Let's be perfectly clear for the benefit of the hard-core overclockers among our readers: there is nothing more you can do at this point to squeeze any more speed out of this CPU. The step up to 3.2 GHz is simply too big, because of the 90 nm fabrication process used to build this processor.

Nvidia's SLI functions offer a great value-added proposition. With hyper-expensive RAM, the Athlon FX-62 attains memory clock rates of DDR2-1016.

Only when used in concert with very expensive Corsair DDR2 memory modules can you think of attaining the kinds of performance levels that we report in our benchmarks. This increases memory throughput from 9.2 GB/s to 10.7 GB/s - a noticeable improvement over what Intel can deliver. This is where the built-in memory controller really pays big dividends for AMD. Command T1 access proved impossible for this memory at speeds of 508 MHz or higher. We used the heavily tricked-out Asus motherboard known as the M2N32-SLI Deluxe with this processor. Our engineers were able to play with settings on this board to their heart's content.

Despite memory throughput speeds of 10.7 GB/s, the tuned-up Athlon FX couldn't compete against the equally tuned-up Core 2 Extreme.