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Reviewed by: Carl Nelson [02.20.05]
Manufactured by: Intel


Not a Moment Too Soon

When AMD introduced the Athlon64 CPU in September 2003, Intel's response was "so?". Although the A64 was important in bringing 64 bit to the desktop while retaining full 32 bit capability, Microsoft has yet to release its x64 version of Windows XP to the public. And believe me, in all my time searching for real-world applications compiled in 64 bit for testing in the article, I came quite short.

Just last week, Microsoft released the latest RC build of Windows XP x64. It looks like it's time to gear up for the final version, with final drivers and final 64 bit applications bound to be released shortly after. Finally.

So it seems quite appropriate that Intel is launching their 600 series of P4's today. Although we usually question the timing of launches such as this (midnight on a Sunday, on a long weekend no less), but this time it seemed to work out ;)

There are a few other tricks up the 600's sleeves however; and at the same time, we'll be looking at the latest Extreme Edition, which has moved over to the Prescott core.


It is a rare occasion that we can link directly to stores where you can buy a product when doing a 'first look' review, but as you can see on the top of the page, has them in stock and ready to go! In every speed from 3.0 GHz all the way to 3.6 GHz - this is anything but a paper launch. However the Extreme Edition is absent.

New for Pentium 4 600

EM64T or 'Extended Memory 64 Technology'. Like the Athlon64, the Pentium 4 gets its 64 bit capabilities via extensions, as opposed to being a 64 bit only part. EM64T is not compatible with code compiled for Intel's other 64 bit part - Itanium. For the full details, check out Intel's Developer's Guide.

2MB L2 Cache - This is what made the Extreme Edition so special, before it got the 1066 MHz FSB. Now the 'high end' (as opposed to 'ridiculously high end') Pentium 4 gets it. We'll have more details and a chart later on.

EIST and C1E Halt State - EIST - or Enhanced Intel SpeedStep - in combination with C1E Halt State is a godsend to frustrated Pentium 4 users who found the heat generated by the Prescott gave them issues (usually related to other parts overheating, as the P4 can stand quite high heat levels before having to be throttled down). EIST works a lot like it does on the Centrino platform - the multiplier is set to a low level when CPU usage is not very high. For instance, while browsing web pages or writing emails. When the CPU has to kick in, to play games or processing images, etc, the multiplier is raised, and the CPU runs at full speed. This is all transparent to the user, and works flawlessly in my experience.

We already know about XD bit (Execute Disable), which got the "J" suffix on 500 series P4's. This is a security measure introduced in SP2 to help prevent attacks such as buffer overflows.

To the disappointment of some, the Frontside bus of the 600 remains at 800 MHz, even though the Prescott is perfectly capable of handling the higher 1066 MHz used by Extreme Edition. Wondering why? It mostly has to do with the Extreme Edition's transition to the Prescott platform:

New for Extreme Edition

90nm Prescott Core - Well the newest feature of the Extreme Edition is the fact that it has moved from the Northwood core to the Prescott. I guess 3.46 GHz was as high as Intel felt comfortable taking that core. This means that the EE gets all the features introduced with Prescott, include SSE3, better prefetching, better Hyperthreading. Unfortunately the negative aspects are inherited as well, such as the uber long data pipeline, and of course heat.

2MB L2 Cache - We're used to seeing the Extreme Edition carry 2MB of L3 cache. This time, it is on the L2 cache, just like the regular Prescott 600 series.

EM64T - Extreme Edition also gets EM64T. It also gets XD bit.

However one thing the EE doesn't get - and should have in my opinion - is Enhanced SpeedStep. I can see where Intel is going with this though; they want to designate the Extreme Edition as being "all out crazy ass performance y0!!". If you want to be EXTREME, you don't give a $#!+ about heat!

One thing that should be apparent by now is that the 600 and Extreme Edition are pretty much identical now. The die sizes and transistor counts are identical. The only thing separating them now is clock speed and Frontside bus speed. When the Extreme first moved to 1066 FSB, we were less than impressed. We speculated that Prescott would benefit much more from such a high bus rate, and now we get to find out if that was true.

CPU Chart

To get a quick glance of how processors are designed, here's a quick chart of features, speeds, and sizes:

  Clock Speed (GHz) Bus Speed / FSB or HTT (MHz) L1 / L2 / L3 Cache (KB) Fab Technology (nm)
P4 660 3.6 200 / 800 16 / 1024 90
P4 560 3.6 200 / 800 16 / 1024 90
P4EE 3.73 3.73 266 / 1066 16 / 2048 90
P4EE 3.46 3.46 266 / 1066 8 / 512 / 2048 130
A64 3000+ 1.8* 200 64 / 512* 90
A64 FX55 2.6 200 64 / 1024 130

* = For reasons we have yet to figure out, AMD CPU's often come in different configurations, even when carrying the same model name. In this case, our 3000+ is a Winchester core, clocked at 1.8 GHz, and has 512KB L2 cache. There are several other AMD CPU's named 3000+ with varying clock speeds and cache sizes (and even CPU generations). Anything from a Barton AthlonXP to a Sempron to more than a few Athlon64's... AMD has pretty much thrown their naming scheme out the window, and I get a headache just thinking about it.

Windows XP x64

As I mentioned above, Windows XP x64 is at Release Candidate 2 now, and that usually means Gold is not more than a few months away. Of course there are some things you should know before diving in with your Athlon64 or P4 600.

First of all, to get any true benefit from 64 bit memory architecture, you're going to need to use programs compiled for a 64 bit OS. I have looked all over for 64 bit applications to benchmark, and came away pretty much empty handed. Don't get me wrong - there are a few benchmarks floating around, but many of them were released by AMD for the Athlon64 launch, and some are compiled directly for use with Athlon64 processors.

Windows XP 64 can technically run 32 bit apps just fine - this is called "Windows on Windows 64" mode or "WoW64". This essentially translates 32 bit functions to 64 bit mode. This is seamless, and technically perfect, but there are many issues you could run into.

For instance, many application installers will look for the supported OS type - if you are installing Xpand Rally for instance, it will check if you're running Windows XP, Windows 2003, etc. Since Windows XP x64 is not directly supported, the game will not run. I also had other odd errors, like Unreal Tournament 2004 not recognizing the CD key, and Microsoft programs like Windows Media Encoder would not install at all.

We did run some tests to compare WoW64 on the Extreme Edition and FX55, but I think I will leave full coverage for another article; perhaps later this week. I would really feel uncomfortable publishing results on a beta OS, with beta software, beta drivers. Things could change drastically from now until WinXP x64's final launch date.

For now, let's get back to good old 32 bit Windows XP performance. We have a ton of benchmarks for you this time...

Next Page: (Benchmark Config, Price Chart)