Intel Core 2 Quad Performance: FSB

Page 1: Introduction

It's been less than a year since Intel launched its first quad-core processor, Kentsfield. Even though the competition may define "quad-core" differently, the fact remains that Core 2 Quad contains four processor cores, and it's been a very successful processor for this relatively short period of time. The clock frequency has scaled from the initial 2.67 GHz to 3 GHz, but there's a lot more to it than just frequencies. Core 2 Quad series hasn't just been expanded to include QX6850, QX6800, Q6700 and Q6600, but thanks to a new stepping, Intel has also managed to reduce power consumption and heat significantly. The motherboards of today are getting better and better at handling high system bus frequencies of quad-core processors, which also made it possible to raise the bus from 266 MHz to 333 MHz with the QX6850 model.

We dissected the Kentsfield architecture in a previous article, basically we're talking about two merged dual-core processors. Back then we concluded that such a solution could be bottlenecked when the processor sends data between the two pairs of cores. This information is namely sent through the common system bus, which is a lot slower than a direct path between cores in the same die. This should also mean that the performance should improve if we raise the system bus, also known as the FSB. That is precisely what we're going to investigate in this article, and we will not settle for just comparing 266 MHz and 333 MHz FSB.

Let's take a look at the test system.