Sandy Bridge: What’s Inside?
Being new generation microarchitecture, Sandy Bridge processors bring a lot of enhancements and new technologies to the table. You can notice that they are very different from the previous generation Nehalem microarchitecture in many aspects. But the most remarkable thing about the new Sandy Bridge processors is much higher level of processor die integration. The tendency towards moving chipset North Bridge functionality into the processor has been established long time ago, but it is for the first time that all computational cores, cache-memory, memory controller, PCI Express bus controller and graphics core - all met inside the same semiconductor die of mobile and desktop processors.
Thanks to this close vicinity of all major components inside the contemporary system, Intel engineers managed to make them interact in a highly efficient manner. The graphics core seems to be in the best position in this case, as it now has direct access not only to the memory controller, but also to all other processor components, such as L3 cache. The computational cores also weren’t forgotten: the use of a unified processor ring bus allowed increasing throughput along all major data transfer routes.
Thanks to finer 32 nm process, which was perfected over the entire 2010 using Clarkdale and Arrandale processors as a run-in platform, they could combine almost all major components of a computational system inside a single semiconductor die. Sandy Bridge die turned out even smaller than Lynnfield, which indicates that they will cost less to make.
Compact Sandy Bridge semiconductor die allows Intel to push their CPUs with new microarchitecture in multiple market segments, even those where graphics core won’t be used at all. This is a perfect example of a situation, when it is cheaper to disable part of the CPU rather that design a completely different semiconductor die. But in the lower price segment they will be offering special “light” die modifications, with a graphics core and only two processor cores inside.
This week first quad-core processors with new Sandy Bridge microarchitecture should become widely available for purchase. They will be positioned for the mainstream price segment. We should expect to see less expensive dual-core models to hit the stores in about a month.