Overclocking
You may have already heard some of the hype about overclocking headroom in the Phenom II. Of course, such things are never guaranteed, but a willingness to reach higher clock speeds could bode well for AMD's 45nm quad-core processors. And, given that the Phenom II X4 940 comes as a Black Edition with an unlocked multiplier, overclocking it could be incredibly easy. Also, AMD probably needs a little additional headroom in these chips to match the 45nm Core 2, which has long been an excellent overclocker.

Our Phenom II X4 940 didn't quite reach the near-4GHz heights that we saw in AMD's early press demo, but it did pretty well with only the assistance of our large-ish Cooler Master air cooler. Here's a quick log of my overclocking attempts and their results. I was using a multithreaded version of Prime95 for stress testing, generally only testing for a few minutes at each speed grade during my initial attempts.

3.2GHz, stock voltage - Seems OK
3.4GHz, stock voltage - P95 thread error
3.4GHz, 1.3625V - Seems OK
3.6GHz, 1.3625V - Immediate P95 error
3.6GHz, 1.3875V - P95 errors
3.6GHz, 1.4V - P95 error, thread 4
3.6GHz, 1.4125V - P95 errors
3.6GHz, 1.425V - Seems good, temps at ~41C
3.8GHz, 1.425V - Crash during boot
3.7GHz, 1.425V - Crash during boot
3.7GHz, 1.45V - Crash during boot
3.7GHz, 1.475V - Crash during boot
3.7GHz, 1.4875V - Crash during boot
3.7GHz, 1.5V - Crash during boot
3.7GHz, 1.525V - Crash during boot
3.7GHz, 1.55V - Crash during boot

Back to 3.6GHz, 1.425V - Crash during boot
Stock speed and voltage - Boots fine
3.6GHz, 1.4375V - BSOD!
3.5GHz, 1.425V - Seems OK, temps at ~40C

Getting the system to boot into Windows at 3.7GHz proved to be impossible, even at 1.55V. As you can see, I eventually settled on 3.5GHz as a nice, stable overclock.

I was close to 3.6GHz, but things seemed to go downhill as I raised the voltage, which is never a good sign. Perhaps with a little more tweaking this CPU could make it over the hump at 3.6GHz or better, but I didn't have time to nurse it along. For what it's worth, fellow TR editor Geoff Gasior made his own attempts with a different Phenom II X4 940 chip, and he tells me his was stable at 3.5GHz and 1.4375V using a Scythe Ninja cooler.

The Phenom II's performance was already strong in both of these games at stock speeds. When overclocked to 3.5GHz, the Phenom II is nipping at the heels of the Core i7-965 Extreme.