Prepare to say goodbye to the Pentium as we reveal the next generation
Finally, a desktop chip based on Intel’s amazingly low power and fast Core micro-architecture is here. Not only that, but it’s based on a new Core 2 design, which takes the same principle of high performance with low power and extends it further. The good news is that desktop Core 2 comes in the same LGA775 package as Pentium D and Pentium 4 parts, meaning many existing boards will support it as a drop-in replacement after a BIOS update.
The new design
Reducing the power consumption of a processor is easy: just take down the transistor count or reduce the clock frequency. Transistors consume most of their power when they’re in the process of switching from one state to another, so the slower their switching frequency the less power they consume.
The problem comes when you need to reduce power consumption while increasing computing performance. But Intel has managed this in spectacularly effective style. The new Core 2 designs have reduced clock speed while increasing the average number of instructions executed per clock cycle, giving faster performance. The company is keen to point out that Core 2’s speed comes from a combination of new design features and evolutions in existing engineering techniques. Its new catchphrase is the 40/40 design proposition: getting 40 percent more performance for 40 percent lower power consumption.
The micro-architecture may share many features with the original Core, but Intel engineers stressed to us that Core 2 is the first ‘real’ Core, designed from the ground up and cherry-picking features from many of Intel’s previous CPUs. The design process was started in great secret when Intel began to realise that the NetBurst deep-pipeline, high-clock-speed approach lead to unacceptably high power consumption and lacklustre performance.
The basics of Core 2’s specification are straightforward enough. The major inclusion that makes it suitable for a general roll-out across server, workstation and desktop product lines is 64-bit capability, with support for EM64T instructions. Along with that, there’s a total of 4MB of Level 2 cache in the highest performance parts, and 2MB in the lower-end models. All but the lowliest models boast a front side bus speed of 1066MHz, a speed previously found only in top-end Extreme Edition CPUs. Like the original mobile Core Duo, the Level 2 cache is shared between the two cores (see below).
The fabrication process is the same 65nm process introduced with Core and later Pentium D designs.
The new models
The new range starts with the Core 2 E4200, a bottom-end part with only 2MB Level 2 cache, 800MHz FSB and a 1.6GHz clock speed, and rises to the Extreme Edition X6800, which boasts a 2.93GHz clock, the full 4MB Level 2 cache and a 1,066MHz FSB. The top-end standard desktop part is the E6700, which shares the same specification as the Extreme Edition but runs at 2.66GHz. The Extreme Edition is markedly different to previous Intel chips: whereas the previous model, the Pentium Extreme Edition 955 (March 2006, page 87), differed significantly from the Pentium D processors with its dual HyperThreading cores and larger cache, the X6800 really is simply a Core 2 with its clock multiplier unlocked. This was verified by slowing it down to a 10x clock multiplier -- giving a 2.66GHz clock speed -- at which setting it achieved exactly the same benchmark score as the standard E6700. The overclocking ability is sound; using a stock Intel heatsink, the board went up to a speed of 3.2GHz for a benchmark score of 1.84, and the reported temperature didn’t rise above 65 degrees.
| Model | Clock speed | L2 Cache | FSB |
|---|
| E4200 | 1.6GHz | 2MB | 800MHz |
| E6300 | 1.86GHz | 2MB | 1066MHz |
| E6400 | 2.13GHz | 2MB | 1066MHz |
| E6600 | 2.4GHz | 4MB | 1066MHz |
| E6700 | 2.66GHz | 4MB | 1066MHz |
| X6800 | 2.93GHz | 4MB | 1066MHz |
