Introduction and Processor Specifications

Intel has added SpeedStep technology, 64-bit extensions, Execute Disable Bit and an extra MB of L2 cache to the P4 line and the Extreme Edition processor. Is it enough to cut the distance to the Athlon?


If you have been keeping an eye on the processor release schedules of certain manufacturers, you may have noticed a trend when it comes to Intel’s: they have been on Sundays.  While at first that may not seem like an important issue, it can give you a quick estimate as to how well received the new products are going to be.  A product released on a weekend isn’t going to get as much attention from readers, analysts and investors as products released on Monday.  So again, Intel announced their 6xx series of processors as well as a new Extreme Edition processor quietly on Sunday morning as millions around the world prepared to watch the Daytona 500.

The Intel 660 Processor

The new 6xx series of processors, shown here in its fastest form, the Intel 660, is still based on the Prescott core but adds a new list of features to the lineup.  They include:

  • EM64T – Extended Memory 64-bit Technology is the term that Intel has given its implementation of the 64-bit extensions developed by AMD for the x86 architecture.  The AMD Opteron and Athlon 64 line of CPUs have had this technology in them for over two years now, though they have yet to be really utilized in any fashion as no Windows operating system supporting 64-bit processing was available for the consumer.  With the arrival of that OS getting closer, Intel was finally forced to implement the feature set in their desktop parts. 
  • Execute Disable Bit – Another technology that was first introduced in the Athlon 64 line of processors, the idea behind this technology is to allow the processor to denote certain areas of main memory as “non-executable” and thus preventing some of the basic security threats from occurring on properly configured systems.  Windows XP SP2 is required for support of this feature.

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The Intel 660 Processor

  • Enhanced SpeedStep – Intel’s term for the feature they have included on their moblie processors for some time, this technology allows the processor to scale down its overall speed, by lowering both the system bus and the multiplier and voltage, when the processor is idle.  This allows the processor to save power and generate less heat when it is in a stand by mode.  This does not help the heat and power issues of a fully operational battlesta…er Pentium 4. 
  • 2MB L2 Cache – If you were looking for a performance advantage to the new 6xx series processors, this is it.  Moving from a single MB of L2 cache to 2 MB of L2 cache is an attempt by Intel to improve overall system performance.  With the extra cache, the processor can store more data locally and there by be required to access the main system memory, which is exponentially slower, fewer times.  While twice the L2 cache doesn’t mean you’ll see half the memory accesses, it will improve scores in our benchmarks. 

The rest of the processor remains the same as their 5xx series cousins: 800 MHz FSB, 31-stage pipelines, etc.  The frequency of the 660 is the same as the 560 chip: 3.6 Ghz.  The number of transistors has moved up to 169 million with the addtional feature and cache and the die size has increased to 135 mm squared.  We’ll leave the benchmarks to decide if Intel has made enough of a change in the CPU to catch AMD’s Athlon 64 line.

The Intel 3.73 GHz Extreme Edition Processor

Believe it or not, the 3.73 GHz XE is the most revolutionary change in the Extreme Edition processors since they were introduced.  What has been changed here on the latest XE from Intel:

  • EM64T – Just like in the 6xx series of processors, the new 3.73 XE chip includes support for the 64-bit instruction set.
  • Execute Disable Bit – The Extreme Edition processors now pick up this feature that both the 500J series and the 600 series include for added security

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The Intel 3.73 GHz Extreme Edition Processor

  • 2MB L2 Cache – Taking a big step from previous Extreme Edition processors, the new 3.73 GHz chip has 2MB of L2 cache instead of the previous 2MB of L3 cache.  This is actually a big improvement in performance for the processor, as L2 is both faster and exclusive in the Intel architecture. 
  • 90nm Prescott core – That’s right, the Extreme Edition processors have now moved over to the Prescott core, meaning a longer pipeline, lower performance per clock, but added performance in certain applications.  We’ll show where this benefits, and where it doesn’t, in our benchmark suite.  It looks like the death of the Gallatin core is FINALLY here. 

The rest of the XE processor feature set remains including the 1066 MHz FSB speed over the standard 800 MHz on the 500 and 600 series of chips.  No SpeedStep technology was implemented however.  In fact, that is really all that differentiates the two processor lines at this point, since both are now using the Prescott core. 

Since both processors now share almost the exact core, here is a shot of the new 600 series core:

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Intel 660 Core Image

Notice that the L2 cache, located at the bottom in this image, takes up about half of the total die space.  

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