Compaq W4000 Manual De Usuario

Chapter 3  Processor/Memory Subsystem 

 

 

These systems each feature an Intel Pentium 4 processor in a FC-PGA478 package mounted with 
a passive heat sink in a mPGA478B zero-insertion force socket. The mounting socket allows the 
processor to be easily changed for servicing and/or upgrading.  

 
 

 
The Intel Pentium 4 processor represents the latest generation of Intel’s IA32-class of processors. 
Featuring Intel’s NetBurst

 architecture, the Pentium 4 processor is designed for intensive 

multimedia and internet applications of today and the future while maintaining compatibility with 
software written for earlier (Pentium III, Pentium II, Pentium, Celeron, and x86) microprocessors.  
Key features of the Pentium 4 processor include: 
 
♦  Hyper-Pipelined Technology – The main processing loop has twice the depth (20 stages) of 

the Pentium III allowing for increased processing frequencies. 

♦  Execution Trace Cache –  A new feature supporting the branch prediction mechanism, the 

trace cache stores translated sequences of branching micro-operations (

µops) and is checked 

when suspected re-occurring branches are detected in the main processing loop.  This feature 
allows instruction decoding to be removed from the main processing loop. 

♦  Rapid Execution Engine – Arithmetic Logic Units (ALUs) run at twice (2x) processing 

frequency for higher throughput and reduced latency. 

♦  256-KB Advanced transfer L2 cache – Using 32-byte-wide interface at processing speed, the  

L2 cache can provide 48 GB/s performance (3x over the Pentium III) 

♦  Advanced dynamic execution – Using a larger (4K) branch target buffer and improved 

prediction algorithm, branch mis-predictions are reduced by an average of 33 % over the 
Pentium III. 

♦  Enhanced Floating Point Processor  - With 128-bit integer processing and deeper pipelining 

the Pentium 4’s FPU provides a 2x performance boost over the Pentium III. 

♦  Additional Streaming SIMD extensions (SSE2) – In addition to the SSE support provided by 

previous Pentium processors, the Pentium 4 processor includes an additional 144 MMX 
instructions, further enhancing: 
•  Streaming video/audio processing 
•  Photo/video editing 
•  Speech recognition 
•  3D processing 
•  Encryption processing 

♦  Quad-pumped Front Side Bus (FSB) – The FSB uses a 100-MHz clock for qualifying the 

buses’ control signals.  However, address information is transferred using a 200-MHz strobe 
while data is transferred with a 400-MHz strobe, providing a maximum data transfer rate of 
3.2 GB/s. This is a boost of over three times that of a Pentium III with a 133-MHz FSB.  

 
 

 

 

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