Core i7 CPU

So what about overclocking?
With the introduction of a new CPU, there’s always the off-chance that it will be a dud overclocker. One that is so depressingly average that it refuses to be pushed, and simply throws instabilities and errors at you until you’re blue in the face (most likely from the light of the BSOD on your screen).
Thankfully this is not the case with Nehalem. Overclocking is still performed through the BIOS, and is still easy enough that the thousands of people currently playing with their Core 2s will be able to play around with Nehalem in a very similar manner. The hardest barrier that we found was knowing where to add voltage to get the chip stable – once we found this, overclocking was a very pleasant experience.

Even though we know Nehalem doesn’t use the FSB any more, it is still dependant on the frequency of the QPI bus to determine its working speed. So armed with our i965 and the 24x multiplier available, we set about pushing it in ways that Intel would like to pretend never happens. With a stock QPI frequency of 133MHz, this gives us 3192MHz (essentially 3.2GHz). Just like the FSB, all that’s required to overclock Nehalem is to increase this bus speed, done by simply entering in a larger number in the BIOS. We bumped this straight up to 150MHz for a test run and found a few instabilities – so the Vcore was raised from a stock of 1.25V to 1.3V, bringing us into Windows at a very comfortable 3.6GHz.

Not content with that small bump, we sat down with this board over the course of a day, and coaxed the highest speed out of this chip that we could – 3.936GHz with a frequency of 164MHz. To get this stable, we had to add voltage to the core (1.4725V), the QPI link (1.3V) and the memory controller (1.28V). This was all done on air cooling, so expect much better results on water or subzero cooling – especially with the large amount of heat generated by all four cores.

Verdict – Is Nehalem Worth it?
The answer is a resounding yes! With performance increased over the current wave of CPUs by an extremely large margin, and multithreaded performance in excess of what we’ve ever seen from a multicored CPU, Nehalem is an amazing chip. While it will take a while for Nehalem to trickle down into the affordable range (the RRP of the i965 is $AU2600, more or less), the good news is that prices in other Intel chip ranges are already dropping – so even if you don’t get Nehalem straight away you can still grab yourself some great performance thanks to this release.

We, for one, worship our new Nehalem overlords – and you should too.