Intel has finally launched a successor for Pentium 4. Its name is Core 2 Duo and it is the first desktop CPU to use the new Core microarchitecture. In this tutorial we will list all Core 2 Duo, Core 2 Quad and Core 2 Extreme models released so far and will talk about their main features.

Core 2 Duo processor (codenamed Conroe) starts a new CPU generation from Intel based on the new Core microarchitecture (as Core 2 Duo is the first desktop processor to use this microarchitecture) and declares the end of Netburst microarchitecture used by Intel’s 7th generation processors, which is around since 2000. As Core microarchitecture is based on the same architecture used by Pentium M and Pentium III, we can say that Core 2 Duo is a 6th generation Intel CPU. Besides Core 2 Duo, Core 2 Quad, Core 2 Extreme and Xeon series 5100 (codenamed Woodcrest) use this new microarchitecture.

Core 2 family comes in three flavors: Core 2 Duo, which replaces Pentium 4 and Pentium D, Core 2 Quad, which is a quad-core Core 2 Duo, and Core 2 Extreme, which replaces Pentium Extreme Edition. The difference between Core 2 Duo and Core 2 Extreme is that the last one runs at higher clock rates and has its clock multiplier unlocked, which allows you to overclock the CPU by changing the CPU clock multiplier. Some Core 2 Extreme models have four CPU cores, as you will see on the next page.
 
Pay attention to not confuse Core 2 Duo with Core Duo. Core Duo is the commercial name for a Pentium M manufactured using 65 nm process, codenamed Yonah, while Core 2 Duo is the commercial name for the CPU codenamed Merom (for laptops) or Conroe (for desktops), which uses the new Intel Core microarchitecture. For an in-depth discussion on this new microarchitecture, read our Inside Intel Core Microarchitecture tutorial.

Here is a summary of the main Core 2 family features:

• Core microarchitecture.
• 32 KB instruction L1 memory cache and 32 KB data L1 memory cache for each core.
• Dual-core technology or quad-core technology.
• 65 nm manufacturing process.
• Socket 775.
• 800 MHz (200 MHz x 4), 1,066 MHz external clock rate (266 MHz x 4) or 1,333 MHz (333 MHz x 4).
• 2 MB, 4 MB or 8 MB unified L2 memory cache.
• Intel Virtualization Technology. (Except on Core 2 Duo E4300)
• Intel EM64T Technology.
• SSE3 instruction set.
• Execute Disable Bit.
• Intelligent Power Capability.
• Enhanced SpeedStep Technology.

On Figure 1 you can see a picture of a Core 2 Duo CPU die.

click to enlarge
Figure 1: Core 2 processor die.

Let’s now talk about Core 2 Duo and Core 2 Extreme models launched so far.