Intel's new Core i7 architecture uses DDR3 memory, which considering Intel's tendency to push the latest and greatest is a surprisingly familiar reference point at a time of new chipsets and CPUs. However, not everything is as it seems.
Core 2 used DDR2 or DDR3 memory in dual channel mode with an emphasis on clock speed, to reduce the inherent disadvantages of locating the memory controller in the Northbridge of the chipset. The Intel P35, P45, X38 and X48 chipsets would happily run memory at an effective speed of 1,600MHz which is a true clock speed of 800MHz (we won't get into the intricacies of this here but from now on we are going to stick to effective speeds in this review to avoid confusion).
Nvidia went a step further with its nForce 790i SLI chipset which could clock suitable memory to 2,000MHz, as we saw with the Asus Striker II Extreme, although the fastest memory we could use during the review would 'only' run at 1,600MHz.
The problem is that fast memory costs a fortune with 2GB of Kingston's KHX13000 costing £345 earlier this year.
Today you can buy 2GB of OCZ DDR3-2000 for £224 which is a definite step in the right direction but very few of us wish to spend even that sort of cash on memory. Those sorts of prices also delay the move to 64-bit Windows as the prospect of 4GB or 8GB of performance RAM is little short of terrifying.
Core i7 changes the terms of the DDR3 arms race as the memory controller is now part of the CPU. This makes the communication path shorter, which in turn reduces latency between the CPU and its memory, while the move to a triple channel memory controller increases bandwidth by 50 percent in the blink of an eye. It also means that the majority of X58 motherboards have six memory slots so it is quite logical to install 3GB of RAM on a 32-bit OS instead of the usual 2GB.
Core i7 puts a significant emphasis on power saving and the Asus P6T Deluxe motherboard we are using as a test bed comes with a warning sticker which states that using more than 1.65V to power the memory on a Core i7 motherboard may permanently damage your processor.
That 1.65V figure is well within the JEDEC specification for DDR3 but it is considerably less voltage than we are accustomed to using. The Kingston KHX13000 that we mentioned runs at 1,625MHz using 1.9V while the slower KHX11000 requires 1.7V to hit 1,375MHz.
The reduced RAM voltage figure ties in with a maximum official memory speed of 1,066MHz for Core i7 so Crucial's PC3-8500 may sound horribly slow with its speed of 1,066MHz but it is actually at the cutting edge, so to speak. Each 1GB module has timing figures of 7-7-7-20 and runs at 1,066MHz on 1.5V which does at least mean that you don't have to mess about with power settings in the BIOS to get your new memory running at the correct rated speed.