At 'just' 375MHz FSB, the Intel Core 2 Due E6420 jumps to a net operating speed of 3GHz, which is more than adequate to displace the fastest dual-core desktop processor (X6800) at a fraction of its cost. With 1333MHz PSB (or 333MHz FSB) soon to become a norm and from our overclocking experience with a variety of motherboards, a jump to 375MHz is very much within means of a vast majority of Intel P965 and the new Intel P35 motherboards. In fact we could only think of boards with the most restrictive BIOS controls not being able to offer this capability.
By contrast, an E6320 would require an FSB overclock well over 425MHz to reach 3GHz. Herein lies the need for a more capable motherboard, and a good BIOS with the necessary overclocking controls. Not all boards are endowed with this and more often then not, you'll need to spend more on motherboard models renowned for overclocking if you take on the Intel E6320 route.
To rule out any bottlenecks in our overclocking article, we prepared a system based on the ASUS Commando motherboard (Intel P965) which holds the record here in www.hardwarezone.com of the highest FSB overclock attained to-date. After much trial and error, we attained the highest stable overclock with the E6420 processor at 3.23GHz - all on air-cooling with the stock cooler. Not exactly as high as what we cranked out with the E6300 previously, but they are in the same ballpark as far as overclocking headroom is concerned. Though we were hoping to hit this frequency without any modifications to the BIOS settings other than the FSB speed and the correct memory multiplier, a little more juice was needed. With a slight voltage boost to the E6420 processor at 1.4V and 1.3V to the Northbridge chip, we attained a rock stable clock speed of 3.23GHz at 404MHz FSB. That's not difficult to achieve at all and as our article title resonates - it is almost effortless. Here's a few CPU-Z screenshots for some CPU/system information before we bring on the results segment to show you exactly what an E6420 @ 3.23GHz can do for you:-