Intel’s biggest just got bigger...
When the Nehalem architecture first came out last year, enthusiasts and those in the tech world felt an awe that we hadn't felt since AMD trounced Intel with its Athlon CPUs back in the day - and a sudden urge to change our pants. From the wild success of its Core 2 series of CPUs, Intel managed to not only outperform them but do it by a significant margin; packing in an integrated DDR3 memory controller as well as a whole new system interface in the form of the QuickPath Interconnect (QPI).
We looked at their very first chip based on the Nehalem architecture, the Core i7 965, which was clocked at a stock of 3.2GHz and had an unlocked multiplier - as well as a launch price of almost two grand. The new Core i7 975 chip is the successor to the older 965, which is being killed off on the fourth of September this year. It's nowhere near the price of the other one, but is a still-hefty $1695.
Assuming you've got money to rampantly whack down on the table, buying this chip will net you a 45nm quad-core processor that contains all four cores on the one die. It's got a phenomenally huge 8MB L3 shared pool of cache, which feeds into four separate 256KB L2 caches and finally four 32KB L1 caches. All this cache space clocked at a huge speed - thanks to its proximity to the cores - means that bandwidth is huge within the chip. But that's not the only improvement this has over older CPU designs; it also comes with an integrated DDR3 controller that provides access to three memory channels. Three or six sticks of fast DDR3 can be accessed directly by the CPU for huge memory throughput (in some cases more than twice as much as older systems!).
This CPU has a base multiplier of 25x and a stock QPI speed of 133MHz, but thanks to the Turbo Mode feature it can be turned up automatically by the chip itself to get to a 27x multi, effectively giving a speed of almost 3.6GHz. As well as Turbo mode, it also has an unlocked multiplier meaning that you can simply raise the multiplier to increase the speed in steps of 133MHz at a time - in most cases this is the easiest way to increase your CPU speed without having to place much additional stress on the rest of the components on the mobo.
Performance at stock speeds was everything we could have expected of any Nehalem architecture running at 3.33GHz, which unsurprisingly can only be described as awesome. We got very good benchie results in all our tests, and the memory improvements of the integrated memory controller really shine in the memory bandwidth tests of Everest Ultimate. Oddly, version 4.60 of the software would crash when running on this CPU, but version 5.01 would run fine - it's a great tool for anyone interested in monitoring voltages/temperatures or benching their memory.
Overclocking was a pretty standard affair, and we chose one of two methods to get our final clocks. The most straightforward is to simply increase the base clock of the QPI in steps of 3-5MHz a time, increasing voltage when unstable - this places a little extra strain on the motherboard, though. We chose the other method, increasing the multiplier instead and raising the speed in leaps of 133MHz at a time, then finally tweaking the QPI when we reached the most unstable gap. This netted us a final stable result of 4.10GHz, and is a great choice for any enthusiast looking for the ultimate in CPUs.
Issue: 133 | February, 2012