After the big splash made with Core 2 architecture easily dominating two generations of AMD processors and handing leading position back to Intel, the manufacturer is now getting ready to put the Core i7 and Core i7 Extreme Edition, the first representatives of Nehalem architecture, on the market.
In vino veritas
”Nehalem” is henceforth a name synonymous with Core i7 architecture and its different apparitions. Nehalem is a river in Oregon, and a project manager who was also a connoisseur of the region’s wine, chose the name. Wine making is decidedly a rich source of inspiration, as Asus recently showed, giving the label “Pinot Noir” to one of its motherboards...
As is now our habit, we are going to try to understand Intel’s goals in the design of this new architecture and see what the new range of processors is going to bring in terms of how we use our PCs. For once, we won’t have to wait too long as the first Core i7s are expected to be available at the end of the year.
In 2006, Intel left its mark on the world of PCs when it released a processor that had high performance, low energy consumption and was relatively well adapted for all platforms. From the moment it was put on the market, the Core 2 eclipsed AMD’s Athlon 64, which had in turn fairly easily imposed itself on the Pentium 4 and its Netburst architecture. AMD more or less missed its chance for a successful challenger with a weak Phenom and moreover Intel made matters worse with the 45nm Core 2 models that raised the bar another notch. This “miracle” processor, which firmly reinstated Intel as the leader was not by any means a totally new creation. In fact, it is a direct descendant of Mobile processors, initiated under the Pentium M name (Banias et Dothan) and up to the Core Duo (Yonah), the first native dual-core on the market. Keep in mind that these models are the fruit of Intel’s research centres in Haifa, Israel.
Once Mobile, always Mobile
Core 2 clearly has mobile origins, and although it gives excellent results on all types of platforms (desktop PCs, servers and of course portable technology), its design does keep the main strengths and weaknesses of this mobile heritage: obviously design specifications for a mobile processor are different from those of a desktop or server processor.
Indeed, from its introduction, the Core 2 suffered from a certain technological out-datedness: an aging processor bus (in comparison with the K8 HyperTransport bus), an external memory controller (integrated directly to the K8 since 2004!) as well as its dual-core architecture, which, although going further than previous implementations, only preceded the first AMD native quad-cores by 12 months. Intel had to push several innovations back, so as to get the Core 2 released as quickly as possible with the least amount of modification.
Of course, performances weren’t disappointing but in terms of innovation, the Core 2 didn’t represent the same sort of technological leap as did the Pentium 4 when it was introduced in 2000 (even if this didn’t guarantee its success). A fundamentally mobile architecture, Core 2 was able to adapt to the demands of other platforms. However, note that this wasn’t without consequences, in particular in terms of server use as a quad core “assembly” had difficulty with the old bus processor technology or the single memory bus shared by several processors. Also, 64-bit performances fell slightly (some processor capabilities were not activated in this mode). As good as it was in the absolute, the Core 2 never dominated the server platform, in contrast to the Opteron Barcelona, which was designed especially for the job. This goes to show that no processor can be best at everything!
So, this gives an idea of what is at stake with Nehalem, the goal being to cover that which is lacking in the Core 2. Yet how is it possible to come up with an architecture that meets the demands of all platforms? The key is modularity. Nehalem is above all a flexible and adaptable architecture. More Lego than processor, there will be so many versions of the architecture that, even according to Intel engineers, the nomenclature (the commercial naming that is) will be a real headache. This means that many of the different improvements of Nehalem that we will talk about below will not equip all models.
