Core Duo Notebook Processor (CPU)
The Intel Core Duo processor is Intel's first mobile dual core processor for notebooks and a key component of the Intel Centrino processor technology. It belongs to the Core processor family, is based on the Pentium M architecture (two improved Pentium M cores) and the direct predecessor of the Intel Core 2 Duo notebook processors, which were introduced in July 2006.
The Intel Core Duo processor integrates two 32-Bite cores (based on the Pentium M), which are optimised for mobile operation in a single processor. Therewith, it is possible to run threads and application in separate cores with separate CPU resources in parallel and, so, the performance can increase depending on the other hardware components if this feature is supported by the operating system and the software.
Later on the design of the Core Duo was reused for the Pentium Dual-Core (an inexpensive alternative to the Core 2 Duo and a direct competitor of the Turion (64) X2 processors).
Key Features
- Two 32 Bit Cores with shared L2 cache
- Intel Smart Cache – 2MB L2 cache with enhanced Transfer Cache Architecture
- Intel Digital Media Boost
- Intel Dynamic Power Coordination with Dynamic Bus Parking
- Enhanced Intel Deeper Sleep with Intel Smart Cache Sizing
- Intel Advanced Thermal Manager
- Power-Optimized 667 MHz System Bus (all but Uxxxx processors)
- Enhanced Intel SpeedStep Technology Support
- 65nm lithography
Performance
After first benchmarks it gets obvious that the Core Duo is at least equally fast than a Pentium M with same clock speed in all tests. In all applications designed for multi processors the performance is nearly double the performance of the Pentium M (e.g., 86% faster in CineBench).
Technical Specifications
All Core Duo processors are produced in 65 nm technology and have 2 MB level 2 cache. Depending on the model the front-side-bus works either on 667 MHz or on 533 MHz (ultra-low-voltage models). The ultra-low-voltage models require 9.0 Watt, the low-voltage models 15 Watt, all other have an energy demand of 13 Watt. The clock rates of this processor series ranges from 1.06 GHz up to 2.33 GHz. Furthermore, all models implement Intel's Enhanced Speedstep technology, and Execute-Disable-Bit and some of the Intel's Virtualisation technology. The Intel Core Duo is alike the Intel Core Solo and the Intel Xeon dual core processor LV based on the enhanced Pentium M processor microarchitecture.
Enhanced Pentium M Architecture
The Intel Core processor is based on the Pentium M architecture. The Pentium M brings compared to the former mobile IA-32 processors an improved micro-architecture, a lower energy demand and a good performance. The aim was a longer battery life and being ready for new fields of operation by, e.g., enhanced mobility, a very thin shape, integrated wireless LAN. Thereby the following enhancements were implemented:
- Support of Intel architectures with Dynamic Execution
- 32-KByte Instruction-Cache and 32-KByte Write-Back-Data-Cache on-chip
- Up to 2 MByte Second-Level-Cache wich enhanced Transfer-Cache-Architecture
- Enhanced Branch-Prediction and Data-Prefetch-Logic
- Support for MMX-Technology, Streaming-SIMD instructions, and the SSE2 instruction set
- A 400 or 533 MHz Source-Synchronous system bus
- Enhanced Power-Management by Enhanced Intel SpeedStep technology
Dual Core Architecture
The Pentium M architecture was further enhanced for the Core Duo (and the Core Solo). The enhancements include:
- Intel Smart Cache, which improves the data sharing of the two processor cores.
- Enhanced decoding and SIMD execution
- Intel Dynamic Power Coordination and Enhanced Intel Deeper Sleep for reducing the energy demand
- Intel Advanced-Thermal-Manager, which offers digital interfaces to the temperature sensor.
- Support of the performance-oriented 667 MHz bus
- SSE3 enhancement of the instruction set
Dualcore Technik
Two processor cores work inside a single processor component at the same clock frequency and share the L2 cache and the front side bus (FSB).
Execute Disable Bit
prohibits security problems caused by buffer overflows if it is activated and supported by the operating system.
Dynamic Execution
includes deep-branch prediction, micro-data flow analysis, out-of-order execution, superior branch prediction, and speculative execution
Smart-Cache
2 MB Level 2 Cache with enhanced cache architecture make the cache more efficient (compared to the Pentium M architecture).
Advanced Thermal Manager
The Thermal Management system, which was enhanced compared to the Pentium M architecture, improves the control and, therefore, allows quieter, cooler, and slimmer notebooks.
Virtualization Technology (VT)
The Intel VT offers hardware support of virtual systems on a single computer (i.e., using more operating systems in parallel and isolated from each other, e.g., Xen or VMWare).
Digital Media Boost
The Digital-Media-Boost is an enhancement of the micro-architecture, which optimises instructions and improves the performance for the purpose of accelerating calculation intensive tasks like audio, and video processing, picture editing, 3D graphics and scientific calculations.
Energy Saving Functions
Dynamic Power Coordination with Dynamic Bus Parking
On demand both cores are used or vice versa if the performance requirements are not that high one of the two cores will be deactivated.
Enhanced Deeper Sleep with Dynamic Cache Sizing
The enhanced Deeper Sleep allows an even lower minimum voltage than Deeper Sleep and, so, enhances the possibilities to save energy. Dynamic Cache Sizing is also an energy saving mechanism, which allows an automatic memory flush depending on the demands and in idle times.
Enhanced Intel SpeedStep Technology
Depending on the load the SpeedStep Technology allows to switch between different states and to save energy if possible.
Core Duo versus Core 2 Duo
In our special article about the Core 2 Duo processor you can learn about differences between the Core Duo (Yonah) architecture and the Core 2 Duo (Merom).
Models
Processor numbers for the Intel Core CPU are categorized in 4-digit numerical sequences with an alphabetical prefix. All processors with leading 'T' have standard energy demand. Except of these there are also Lxxxx (low-voltage) and Uxxx (ultra-low voltage) processors available.
The following number is based on a variety of
- Cache
- Front side bus
- Clock speed
- Power
- New Instructions
- Other Intel technologies.
Thereby a higher number hints on more features, but this can also mean that a processor features more of an aspect, but less of another.
A detailed list of all models is available in our overview of mobile processors.
A categorization according to performance of all mobile processors is available in our benchmark list of mobile processors.
| Pos | Manufacturer Series' | Model | Codename | FSB | L2+L3 Cache | MHz | TDP (Watt) | |||
| 1 | Intel Core Duo | T2700 | Yonah | 667 | 2 MB | 2330 | 31 | 65 | 2 | |
| 2 | Intel Core Duo | T2600 | Yonah | 667 | 2 MB | 2160 | 31 | 65 | 2 | |
| 3 | Intel Core Duo | T2500 | Yonah | 667 | 2 MB | 2000 | 31 | 65 | 2 | |
| 4 | Intel Core Duo | T2450 | Yonah | 533 | 2 MB | 2000 | 31 | 65 | 2 | |
| 5 | Intel Core Duo | T2400 | Yonah | 667 | 2 MB | 1830 | 31 | 65 | 2 | |
| 6 | Intel Core Duo | L2500 | Yonah | 667 | 2 MB | 1830 | 15 | 65 | 2 | |
| 7 | Intel Core Duo | T2350 | Yonah | 533 | 2 MB | 1860 | 31 | 65 | 2 | |
| 8 | Intel Core Duo | T2250 | Yonah | 533 | 2 MB | 1700 | 31 | 65 | 2 | |
| 9 | Intel Core Duo | T2300 | Yonah | 667 | 2 MB | 1660 | 31 | 65 | 2 | |
| 10 | Intel Core Duo | T2300E | Yonah | 667 | 2 MB | 1660 | 31 | 65 | 2 | |
| 11 | Intel Core Duo | L2400 | Yonah | 533 | 2 MB | 1660 | 9 | 65 | 2 | |
| 12 | Intel Core Duo | L2300 | Yonah | 667 | 2 MB | 1500 | 15 | 65 | 2 | |
| 13 | Intel Core Duo | T2050 | Yonah | 533 | 2 MB | 1600 | 31 | 65 | 2 | |
| 14 | Intel Core Duo | U2500 | Yonah | 533 | 2 MB | 1200 | 9 | 65 | 2 | |
| 15* | Intel Core Duo | U2400 | Yonah | 533 | 2 MB | 1060 | 9 | 65 | 2 |





