Overclocking
In order to check out the overclocking headroom of the new 65nm processors, we moved over to an Asus M2N32-SLI Deluxe motherboard, which has a robust set of overclocking options in the BIOS. The cooler was just a stock unit from AMD.

I started my overclocking adventures with the 5000+. I'll spare you the graphic details, but after quite a bit of experimenting, I was able to get it stable at 2925MHz with a 225MHz HyperTransport clock by raising the voltage to 1.425V in the BIOS—which read as 1.472V in a CPU-Z and in the Asus PC Probe utility. I used two instances of Prime95's torture test to verify stability, and I'd say the 5000+ was a pretty solid overclock at this speed. The 4800+ came close to the 5000+, hitting 2875MHz on a 230MHz bus using the same 1.425V voltage setting in the BIOS.

At these speeds, with dual Prime95 instances running, the 5000+ registered 55°C, while the 4000+ hit 56°C.

These chips are a little odd as overclockers, as early samples from a new fab process sometimes tend to be. They 5000+, for instance, would POST at 3120MHz and boot into Windows just fine, but when I ran Prime95, it wouldn't just throw a computational error when things got bad—it would up and reboot the whole system. There seemed to be little room between stability and "prone to fiery death."

Just to verify that the overclocked CPUs scaled well in terms of performance, here's a look at Cinebench rendering speed. Looks like the overclocked chips scale up more or less as expected. However, the Athlon 64 X2 can't match the Core 2 clock for clock, as the matchup of overclocked 5000+ versus Core 2 Extreme X6800 reminds us.