Intel Core 2 Duo & Core 2 Extreme Processors, Chipsets And Performance Analysis

The Core Microarchitecture


The Intel Core microarchitecture at the heart of the Core 2 Duo and Core 2 Extreme processors is a significant departure from the Netburst microarchitecture used in the Pentium 4 and the Pentium D. There are some brand new technologies employed in the Core microarchitecture that we'll break down on the pages ahead. For now though, here is a condensed list of the features and benefits provided in this new CPU architecture.


Features and Benefits of the Intel Core 2 Duo Desktop Processor: Provided By Intel
Feature Benefit

Dual-Core Processing

Two independent processor cores in one physical package run at the same frequency, and share up to 4 MB of L2 cache as well as up to a 1066 MHz Front Side Bus, for truly parallel computing.

Intel Wide Dynamic Execution

Improves execution speed and efficiency, delivering more instructions per clock cycle. Each core can complete up to four full instructions simultaneously.

Intel Smart Memory Access

Optimizes the use of the data bandwidth from the memory subsystem to accelerate out-of-order execution. A newly designed prediction mechanism reduces the time in-flight instructions have to wait for data. New pre-fetch algorithms move data from system memory into fast L2 cache in advance of execution. These functions keep the pipeline full, improving instruction throughput and performance.

Intel Advanced Smart Cache

The shared L2 cache is dynamically allocated to each processor core based on workload. This efficient, dual-core optimized implementation increases the probability that each core can access data from fast L2 cache, significantly reducing latency to frequently used data and improving performance.

Intel Advanced Digital Media Boost

Accelerates the execution of Streaming SIMD Extension (SSE) instructions to significantly improve the performance on a broad range of applications, including video, audio, image and photo processing, multimedia, encryption, financial, engineering and scientific applications. The 128-bit SSE instructions are now issued at a throughput rate of one per clock cycle effectively doubling their speed of execution on a per clock basis over previous generation processors.

Intel Virtualization

Intel VT allows one hardware platform to function as multiple "virtual" platforms. For businesses, Intel VT Technology (Intel VT) offers improved manageability, limiting downtime and maintaining worker productivity by isolating computing activities into separate partitions.

Intel Extended Memory 64 Technology (Intel EM64T)

An enhancement to Intel's 32-bit architecture to enable the processor to access larger amounts of memory. With appropriate 64-bit supporting hardware and software, platforms based on an Intel processor supporting Intel EM64T can allow the use of extended virtual and physical memory.

Execute Disable Bit

Provides enhanced virus production when deployed with a supported operating system. The Execute Disable Bit allows memory to be marked as executable or non-executable, allowing the processor to raise an error to the operating system if malicious code attempts to run in non-executable memory, thereby preventing the code from infecting the system.

Intel Designed Thermal Solution for Boxed Processors

Includes a 4-pin connector for fan speed control to help minimize the acoustic noise levels generated from running the fan at higher speeds for thermal performance.3 Fan speed control technology is based on actual CPU temperature and power usage.

Better Acoustics

Intel Core 2 Duo processors are equipped with a new Digital Thermal Sensor (DTS) that enables efficient processor and platform thermal control. Thermal sensors located within the processor measure the maximum temperature on the die at any given time. Intel Quiet System Technology, included in the Intel 965 Express Chipset family, uses the DTS to regulate the system and processor fan speeds. The acoustic benefit of temperature monitoring is that system fans spin only as fast as needed to cool the system, and slower spinning fans generate less noise.

Platform Support

A platform based on the Intel 965 Express Chipset family with an optimized memory engine for improved system performance is the ideal compliment for the Intel Core 2 Duo processor. New and enhanced technologies in the area of graphics, sound and manageability offer an array of capabilities. This combination of processor and chipset brings an unparalleled level of performance to the desktop.

The Core 2 Extreme X6800

Shorter Staged Pipeline: Processors based on the Core microarchitecture, like the Core 2 Extreme X6800 pictured here, look just like the Pentium Ds they'll eventually replace in Intel's desktop processor line-up.  The new Core 2 Duo and Core 2 Extreme processors are built using the same LGA775 packaging and will work with many existing chipsets and motherboards.  Looks can be deceiving, however.  The die that lurks beneath that nondescript heat spreader is very different from the Pentium D.  For one, the Core 2 Duo and Core 2 Extreme feature much short 14-stage pipelines, as opposed to the 31 stages used in Netburst-based processors.


Intel Wide Dynamic Execution Overview

Wide Dynamic Execution: The new Core microarchitecture also incorporates Intel's new "Wide Dynamic Execution" technology which enables delivery of more instructions per clock cycle to improve execution time and energy efficiency.  Wide Dynamic Execution gives Core 2 Duo and Core 2 Extreme processors the ability to complete up to four instructions per clock cycle, versus Netburst's three instructions.  Other enhancements in the execution cores include more accurate branch predictors and deeper instructions buffers.

Another important feature of Intel's Wide Dynamic Execution technology is dubbed Macro-Op Fusion. In most current processors, each incoming instruction is individually decoded and executed. But with Macro-Op Fusion, some common instruction pairs can be combined into a single micro-op during decoding (Intel defines a micro-op as a single internal instruction). The two instructions can then be executed as a single micro-op which increases the number of instructions that can be executed in any given length of time. According to Intel, with Macro-Op fusion, instruction loads and micro-ops can be reduced by approximately 15% and 10%, respectively.

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