Date: March 23rd, 2004
Article by: Nathan Glentworth (Owner, Head Editor & Hardware Reviewer)
Product was donated by: Intel
Socket 478 Interface
Front Side Bus : 800Mhz
L1 Cache: 16KB
L2 Cache: 1MB
L3 Cache: None
Rapid execution engine
Execution trace cache
Advanced transfer cache
Advanced dynamic execution
Enhanced floating point/multimedia
Streaming SIMD 2
Intel Prescott Core Information
The Pentium 4 processor with an advanced 800 MHz system bus and supporting Hyper-Threading Technology is available at speeds from 2.40C GHz to 3 GHz, giving breakthrough performance on a variety of desktop PCs†. Hyper-Threading Technology, which was pioneered on Intel's advanced server processors, helps your PC work more efficiently by maximizing processor resources and enabling a single processor to run two separate threads of software simultaneously. The result is greater performance and system responsiveness when running multiple applications at once. So you can multitask like never before.
Intel® NetBurst™ Microarchitecture*
Intel NetBurst microarchitecture delivers a number of innovative features including Hyper-Threading Technology, hyper-pipelined technology, 800 MHz, 533 MHz or 400 MHz system bus, Execution Trace Cache, and Rapid Execution Engine, as well as a number of enhanced features such as Advanced Transfer Cache, Advanced Dynamic Execution, enhanced floating-point and multimedia unit, and Streaming SIMD Extensions 2 (SSE2). Many of these innovations and advances were made possible with improvements in processor technology, process technology, and circuit design and could not previously be implemented in high-volume, manufacturable solutions. The features and resulting benefits of the microarchitecture are defined below.
The hyper-pipelined technology of the Intel NetBurst microarchitecture doubles the pipeline depth compared to the P6 microarchitecture used on previous processors such as the Intel® Pentium® III processor. One of the key pipelines, the branch prediction/recovery pipeline, is implemented in 20 stages in the Intel NetBurst microarchitecture, compared to 10 stages in the P6 microarchitecture. This technology significantly increases the performance, frequency, and scalability of the processor.
Level 1 Execution Trace Cache*
In addition to the 8-KB data cache, the Pentium 4 processor includes an Execution Trace Cache that stores up to 12-K decoded micro-ops in the order of program execution. This increases performance by removing the decoder from the main execution loop and makes more efficient usage of the cache storage space since instructions that are branched around are not stored. The result is a means to deliver a high volume of instructions to the processor's execution units and a reduction in the overall time required to recover from branches that have been mis-predicted.
Rapid Execution Engine*
Two Arithmetic Logic Units (ALUs) on the Pentium 4 processor are clocked at twice the core processor frequency. This allows basic integer instructions such as Add, Subtract, Logical AND, Logical OR, etc. to execute in one-half a clock cycle. For example, the Rapid Execution Engine on a 3.20 GHz Pentium 4 processor runs at 6.4 GHz.
Advanced Dynamic Execution*
The Advance Dynamic Execution engine is a very deep, out-of-order speculative execution engine that keeps the execution units executing instructions. The Pentium 4 processor can also view 126 instructions in flight and handle up to 48 loads and 24 stores in the pipeline. It also includes an enhanced branch prediction algorithm that has the net effect of reducing the number of branch mis-predictions by about 33% over the previous P6 generation processor's branch prediction capability. It does this by implementing a 4-KB branch target buffer that stores more detail on the history of past branches, as well as by implementing a more advanced branch prediction algorithm.
Enhanced Floating-Point and Multimedia Unit*
The Pentium 4 processor expands the floating-point registers to a full 128-bit and adds an additional register for data movement which helps improve performance on both floating-point and multimedia applications.
Streaming SIMD Extensions 3(SSE3) Instructions*
With the introduction of SSE2, the Intel NetBurst microarchitecture extended the SIMD capabilities that MMX technology and SSE technology delivered by adding 144 instructions.
The next generation 90 nm process-based Pentium 4 processor introduces the Streaming SIMD Extensions 3 (SSE3), which includes 13 additional SIMD instructions over SSE2. The 13 new instructions in SSE3 are primarily designed to improve thread synchronization and specific application areas such as media and gaming.
1-MB Level 2 Advanced Transfer Cache*
The 90 nm process-based Pentium 4 processor features 1-MB L2 Advanced Transfer Cache (ATC) compared to 512-KB on the 0.13 micron process-based Pentium 4 processor. The Level 2 ATC delivers a much higher data throughput channel between the Level 2 cache and the processor core. The Advanced Transfer Cache consists of a 256-bit (32-byte) interface that transfers data on each core clock. As a result, the Pentium 4 processor at 3.40 GHz can deliver a data transfer rate of 108 GB/s. This compares to a transfer rate of 16 GB/s on the Pentium III processor at 1 GHz.
Features of the ATC include:
Non-Blocking, full speed, on-die level 2 cache
8-way set associativity
256-bit data bus to the level 2 cache
Data clocked into and out of the cache every clock cycle
*(Information provided by Intel.com)