We received from Intel a Core 2 Duo E6750 engineering sample, which is basically a Core 2 Duo E6700 with a 1,333 MHz FSB instead of 1,066 MHz. It will be launched later this summer together with several other Core 2 Duo models with the new 1,333 MHz FSB, and from the naming used on E6750 we can assume that Intel will use the number “50” on their model numbers to indicate the new external clock rate. Since we also had available a Core 2 Duo E6700 and a Core 2 Extreme QX6700 in our lab, we could make a terrific comparison between these three CPUs – as all three run internally at 2.66 GHz – to answer two basic questions: By how much the new 1,333 MHz FSB will improve PC performance? What is better, a quad-core CPU with 1,066 MHz FSB or a dual-core CPU with 1,333 MHz FSB? Read on.