Conclusions
All told, the Pentium 4 600 series represents good progress for Intel. Power consumption is down, performance is up a bit, and some of the new features are important developments, like 64-bit support and SpeedStep. Unfortunately, the jump from 1MB of L2 cache to 2MB doesn't seem to offer big returns in most desktop applications, but it doesn't hurt, either. I haven't yet tested 64-bit performance, so I won't comment on that, although it's nice to know the capability is in the chip. (We'll look at 64-bit performance shortly in a follow-up article.)

Having said that, I am a little bit conflicted about what to think. The truth is that all of the new capabilities in this processor—dynamic power management, NX bit protection, 64-bit extensions, and better performance than the Pentium 4 500 series—were available in the first Athlon 64 processors that debuted in September 2003. AMD vaulted so far out ahead of Intel in terms of technology and performance that it's taken quite a while for Intel to catch up.

Fortunately for Intel, AMD hasn't done much since the Athlon 64's debut but monkey with cache sizes, add another memory channel, and ratchet up clock speeds a couple of notches. The 600 series is getting closer to the Athlon 64 in terms of overall attractiveness, and AMD needs to answer in order to retain the lead. In fact, if you don't care about playing games on your PC, the Pentium 4 600 series is as good a choice as any. The overall WorldBench scores illustrate the general parity between Intel and AMD offerings at each price point. Given Intel's dominance at the big PC makers, the 600 series is probably as good as it needs to be in order to become a sales success.

One thing that threatens that success is the funky model numbering and pricing mix that Intel has chosen to present to the hapless consumer.

Actually, I take that back. Hap or no hap, it's confusing.

If you'll recall from the beginning of this article, the Pentium 4 550J is priced just five dollars below the P4 640. Overall, the performance race between the two would have to go to the 550J, because 200MHz of clock speed is worth more than the move from 1MB of L2 cache to 2MB. The 550J lacks SpeedStep, but with the C1E halt state, that's quite arguably a moot point. So the decision between the two comes down to this, I suppose: do you want slightly higher performance in 32-bit apps or, for five bucks more, 64-bit capabilities? Ask that of Joe Schmoe and he'll deck you.

I suppose Intel will rely on PC makers to package up the 600 series and make it all work, but the strategy, on the face of it, is confusing. Surely the larger model number with the bigger cache and 64-bit extensions will sell best. Unless consumers buy primarily based on MHz. Is Intel experimenting a little here? Sure seems like it.

I should probably say a word or two about the P4 Extreme Edition 3.73GHz. At its customary price of $999, the Extreme Edition was never a bargain hunter's dream chip. This new 3.73GHz version performs comparably to the previous 3.46GHz one, but no better. The move to a Prescott-based Extreme Edition processor was no doubt inevitable, and the move does bring 64-bit support, but it's an even trade. Go buy an Athlon 64 3500+ if you want a gamer's CPU. It's faster than any Extreme Edition, and you can pocket the $727 you save (or better yet, buy an obscenely expensive graphics card.) Personally, I'd rather have a Pentium 4 660 than an Extreme Edition 3.73GHz. Without SpeedStep or the C1E halt state, the Extreme Edition is less attractive than its 600-series siblings.

Now, there's 64-bit performance testing to be done, so I'll bring this one to a close. Stay tuned for the next chapter.