This is it, this is the real deal! Months and months of speculations, little sneak previews of websites that released info too early and even following threads on overclocking discussion forums in which Intel representatives released small amounts of information; today we can finally show you our review of the Nehalem, no, wait ... Core I7 platform. Contrary to what we'd expect after the release of the 45nm processors, which we tested here
, we now have to forget almost everything we know about the processor, northbridge and memory technology, because it is new, completely new.
But ... what is this new technology exactly? The first and also biggest change is of course the relocation of the memory controller, which used to be in the northbridge (at least on Intel-based systems) but has been transferred to the CPU, much like we've seen AMD do quite some years ago with the Athlon 64 processor. Thanks to the IMC (integrated memory controller), the bandwidth and latency performance should go way up, which means that the bandwidth should’ve increased and the latency should've decreased. Next to that, there's the extra memory channel, which gives the user the possibility to create even more bandwidth when using triple channel instead of dual channel. Whether this extra channel adds anything in terms of real-life performance, you'll be able to read in this review (no squealing!), but do know that certain websites and overclocking forums released information regarding the performance scaling and, it has to be said, it didn't look that well.
Oh, and forget the term 'Front Side Bus', please, because Intel does not use that anymore, the new term is QPI, QuickPath Interconnect, which replaces the functionality of what the FSB was designed for. Actually, we have two new terms that we need to know, well ... new for the normal 24/7 user: BCLK and QPI.
The term BCLK, or base clock frequency, is the clock signal from which the CPU frequency, the QPI frequency and the memory frequency are derived. It has been used in all Pentium Family processors although many people confused it with the FSB. Why? The Front Side Bus, a bus connecting the CPU to the North Bridge, was running at BCLK speed. Over years processors became many times faster but the FSB remained nearly untouched. Intel used AGTL+ bus terminology to have more transactions per second, Quad Pumped like they named it, to increase the system performance since the FSB begin to become a bottleneck. They even increased the bus speed within the same microarchitecture family, now they've finally made the step to go with a totally new approach where the bus interconnection between CPU and chipset has become twice as fast as a FSB running at 400MHz. Named QPI, the new bus should not form any kind of obstacle in system performance for the next few years.
So, the QPI Link Frequency is actually the functional replacement of what used to be the FSB, linking the CPU and the Northbridge, which still is used for peripherals such as the PCIe lanes, and still forms the bridge between the CPU and Southbridge. BCLK has been used in all Pentium Family processors and it does not replace the Front Side Bus in terms of a data bus. It is just a clock signal, nothing else, which has been (re-)decreased to 133MHz, coming from 400MHz.
What else can you find in this article? We compare the performance of this new platform against the QX9770, which is at the moment Intel's fastest quad core, the E8600, which is the fastest dual core, and (of course) AMD's Phenom X4 processor in a series of benchmarks going from raw numbers from Sandra to in-game performance in UT3 to green-minded power consumption tests. And of course, we wouldn't be MAD
shrimps if we didn't include a part regarding the overclockability of the Core I7 both on air cooling as on subzero cooling ...