Last we checked in a big processor benchmark roundup, the 1.8GHz Pentium 4 was trailing close behind the 1.4GHz Athlon. Since then, AMD has laid low, holding back on releasing a new Athlon speed grade. If the Pentium 4 2GHz can catch the 1.4GHz Athlon, Intel will have pulled off a neat double play, reaching 2GHz and retaking the performance lead at once.
We'll investigate whether Intel has accomplished this goal below. We'll also consider in more depth what, if anything, the 2GHz milestone really means to the PC market.
The primary difference between the Pentium 4 2GHz and the previous P4s we've tested is that this one is packaged to fit into Intel's new microPGA 478-pin socket. Intel says Socket 478's extra pins for power and ground connections improve stability for higher clock speeds. The older, larger Socket 423 will be phased out over time, and Socket 478 will supplant it. For the time being, the Pentium 4 will be available in both packages at speeds up to 2GHz.
The P4 2GHz is not the upcoming P4 chip code-named Northwood. It's still built on Intel's 0.18-micron fab process, like all previous P4s, and it's the same basic core design, code-named "Willamette" in a past life. If you want to buy a Pentium 4 now and upgrade to the 0.13-micron Northwood chip later, be sure to get a Socket 478 motherboard. The P4 won't be available in 423-pin form above 2GHz. We've kicked around the possibility of a Socket 423-to-Socket 478 adapter, but if anyone's planning to make one, we haven't heard about it. It certainly seems possible, but obviously its use would be relatively limited.
The 478-pin P4s are teeny little beasts, and Socket 478 takes up what seems like a ridiculously small portion of the motherboard's surface area. Have a look at the pictures to see what I mean.
Despite the differences in physical appearance, the P4 system we're testing today uses Intel's 850 chipset with RDRAM, just like past Socket 423 systems.