The Intel Pentium 4 1.7GHz. Processor
The "Hyper Pipelined" CPU takes it up a notch

By Dave Altavilla - April 24 2001
  

IC Engineering, it's an exacting science.  When a Design Engineer or Engineering Manager sits down to architect his or her next chip, there are a myriad of decisions that must be made that will affect the outcome of their efforts.  Designing a modern day microprocessor is a daunting task. 

When you are doing things from the ground up, as did the Intel design team with the Pentium 4,  you need to design not only with more than just current application and performance expectations in mind but with insight many years into the future.  Just think how long the P6 architecture of the original Pentium processor has been around and you'll get the idea.

  Let's look at one simple aspect that is the yard stick for most modern PC Microprocessors, that being clock speed.  Let's face it folks, when John Q. Public steps into the Computer Superstore with his hard earned cash in hand, most times the clock speed in MHz. is the only number that is stuck in his head.  Now,  the original Pentium processor and P6 Micro-architecture was released at 60, 66 and what was then a blazing 90MHz.  Intel is just now hitting the end of the line with that architecture some 5 years later and at more than 10X its original clock speed.  So, obviously the engineers at Intel needed to design things such that clock speed scalability was a primary feature that would propel them through many years of future roadmap development.

For sure, the number of clock cycles in a given time frame, that a processor can serve up, is a major factor with respect to performance.  However as you are aware, what that processor can do with that incredibly high number of clock cycles, is just as important.  Since its introduction in November of 2000, the Pentium 4 has been turned up well beyond its 1.5GHz. introductory clock speed.  In this article we intend to show you what Intel's latest MHz. Monster can do with those clock cycles, now at a somewhat magical sounding 1.7GHz.

Specifications Of The Pentium 4 NetBurst Micro-Architecure
.18 Micron, 42 Million Transistors with headroom to spare

 

 

 

  • Introductory 1.4GHz. and 1.5GHz. Clock Speed with roadmap to 2GHz. and beyond

  • 400MHz. "Quad Pumped" System Bus

  • "Hyper Pipelined" Technology - 20 stage pipeline depth for greater frequency capability

  • "Rapid Execution Engine" -  ALUs run at twice the speed of the core frequency

  • 256K L2 Advanced Transfer Cache running at core processor speed

  • 8K L1 Data Cache

  • Execution Trace Cache - Caches decoded Micro-Ops readying them for execution

  • Advanced Dynamic Execution - More efficient speculative out of order execution unit feeding execution engines

  • Enhanced Branch Prediction Capability - Compensates for the deeper pipeline's higher likelihood of mis-predicted branches

  • Streaming SIMD Extension 2 (SSE2) - 144 New instructions including 128bit SIMD Integer Arithmetic and 128bit double precision floating point instructions in addition to SSE and MMX instructions.

Click images for full view
 



Here we have your basic Pentium 4 chip.  Yes, it looks the same as the 1.5GHz. CPU that Intel sent us in November, with the small exception of the 1.7G marking on the lower right corner.  We won't go into much detail on the Pentium 4 architecture and its feature set.  If you need a refresher, check our Pentium 4 Bench Test article from November of 2000.  This CPU runs on the same 400MHz. "Quad Pumped" System Bus that is supported by RDRAM and the i850 chipset.  Finally, this Pentium 4 also is based on the same "Hyper Pipelined" technology that drives its 1.5GHz. predecessor and will drive its successors for years to come.  This 20 stage pipeline really allows the P4 to crank up in clock speed.  However, it also means that it will execute less per clock cycle.  In short, this is a sort of "brute force" approach to computing.  If Intel can get the frequency and bandwidth of the P4 up high enough, the MHz. battle can be won against its arch rival AMD, as well as overall system performance leadership.

 

Sounds like good science and engineering, right?  Let's see if things add up.

 

 

Good Cooling,  a new Motherboard from Abit and over-clocking

 

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