P4 Extreme Edition 3.73 GHz, 1066 MHz FSB HT- $999

16KB L1 cache
2MB on die L2 cache
SSE support: SSE SSE2, SSE3
MMX support
EM64T
Enhanced Intel SpeedStep Technology
Execute Disable Bit
90nm
LGA-775 Package
Die Size 135mm2
Transistor Count: 169 million

The first new feature found on the Intel Pentium 4 6xx family and P4 3.73 Extreme Edition is 2MB of on die L2 cache. These CPUs are a 31 pipeline design, giving high latencies compared to the previous Pentium 4s (non Prescotts). One way to alleviate this is to increase the caches. The Pentium 4 5xx series had 1MB of L2 cache, thus the new CPUs have 2X the cache of the previous generation. One interesting note. The Pentium 4 3.46 GHz Extreme Edition has 16 KB L1 cache, 512 KB L2 cache and 2 MB L3 cache. The 3.73 GHz Extreme Edition has 16 KB L1 cache, 2 MB L2 cache. It'll be interesting to see if that makes a difference in performance.

64-bit computing is about to take off in a major way with the introduction of Microsoft's Windows XP-64bit shortly. Intel introduced the 386 processor back in 1985 that had the capability to address up to 4 GB of memory. It's been 20 years, but even last year's Prescott CPUs were only able to address 4 GB of memory. With the introduction of the 6xx family and 3.73 GHz Extreme Edition, Intel enabled 64-bit addressing. This allows up to 256 Terabytes of memory to be addressed.

The Enhanced Memory 64 Technology instruction set is similar in many ways to the instruction set of the AMD Athlon 64 CPUs. The EM64T instructions are an enhancement to the IA-32 architecture. A processor with EM64T can run in legacy IA-32 mode or IA32-e mode. Legacy IA-32 mode allows the CPU to run in protected mode, real address mode, or virtual 8086 mode. IA-32e can operate in two modes: 64-bit mode or compatibility mode. IA-32e can only be used with a 64-bit operating system. Compatibility mode allows the processor to run most 16-bit or 32-bit applications without recompiliaion.

SpeedStep was a technology first introduced in laptop computer processors to extend battery life of the laptop. One thing about computers is that most processors operate at full speed 100% of the time. While this is great for those times when a computer needs it like running games or other heavy applications, there are times when a computer is running Word or other simple tasks where the CPU is not under heavy load. SpeedStep can reduce overall power consumption saving on electricity bills. The way it works is Windows XP detects when the processor load is low and adjusts the frequency of the CPU lower. When the processor load is higher, the frequency is adjusted higher. This is similar to AMD's Cool and Quiet technology.

Viruses have caused many a system to have problems over the years. To offer additional protection against viruses, Intel implemented Execute Disable Bit with their Itanium CPUs. CPUs with this capability can protect data pages against malicious software like (viruses and worms) to execute code. AMD introduced Enhanced Virus Protection with their Athlon 64 CPUs.

Intel is introducing a wide variety of CPUs to fit every budget. The 3.0 GHz P4 is the low end of the 6xx family. At $224, this seems to be a fair price. The 640 CPU to me seems like the sweet spot for this current lineup. With a clockspeed of 3.2 GHz and a price under $300, the performance/price ratio on this CPU should rock. The other features including EM64T, EIST, Execute Disable Bit are all present throughout the line. The 3.73 GHz EE is priced as the high-end gaming CPU and should be treated as such.