Overclocking
Our P4 570J review sample came with unlocked lower multipliers, allowing us to turn down the multiplier and crank up the front-side bus speed. With a little coaxing, I was able to get the P4 570J to boot on our Abit AA8 motherboard with a 1066MHz front-side bus speed and a multiplier of 14, for a CPU clock speed of 3.73GHz.

Oddly, I was forced to back the RAM timings down from 3-3-3-10 to 4-4-4-12 in order to get the system to POST and boot into Windows, even though I'd set the RAM at a 1:1 ratio with the bus. (That should yield an effective 533MHz memory speed, just like the stock config.) Even then, the 1066MHz bus speed wasn't 100% stable, but the system would usually run OK if it made it through POST and successfully booted into Windows.

Once I'd established that the faster bus speed was possible, I started turning up the multiplier. I was able to get the system to POST at 4.54GHz on a 1066MHz bus, but it crashed immediately and refused to POST again. I had more luck at 4.266GHz. I got the system booted into Windows and ran a few benchmarks.

At 4.0GHz and 4.26GHz on a 1066MHz bus, the Prescott was able to make really good use of its memory bandwidth.

Doom 3 frame rates are up a bit, too, but even 4.26GHz isn't enough to catch the Athlon 64 3800+.

I would have run more benchmarks at these speeds, but the system wasn't entirely stable on a 1066MHz bus. We'll have to try again once we get a good tweaker's motherboard based on the Intel 925XE chipset.