Nehalem has garnered quite a bit of attention from industry analysts since the first details were revealed, in 2007. This is because it’s the first time in more than two decades that Intel has completely overhauled the way that data flows between different components on a chip. The overhaul is necessary because, as engineers add more cores to processors, bandwidth becomes a concern, and it becomes harder to prevent data bottlenecks from reducing performance. “It’s a massive redesign,” says Nathan Brookwood, founder of Insight64, an analyst firm. “It has tremendous implications for Intel and all of Intel’s partners.”
Prior to Nehalem, Intel chips had an external memory controller that moved information between the processing cores and the chips’ memory, where frequently used data is stored. Because the controller was separate from the processors, several cores had to share bandwidth. By integrating the memory controllers into the processors, Nehalem has more than three times as much bandwidth. A similar approach was implemented by rival chip maker AMD in 2003, but Nehalem is Intel’s first chip design with such a feature.
Another performance boost comes from the fact that each processor core can accept twice as much data using a feature called multi-threading. As long as software is written to exploit multi-threading, it can effectively transform a dual-core machine into a quad-core one.
Multi-threading is one of the features that will enable Nehalem machines to run more exciting applications. At IDF, Rick Willardson, Intel’s product marketing engineer for desktop CPUs, showed off the winning entry in a contest to find the best new application for Nehalem–a program that quickly searches photo libraries using an original picture as the query. In the demo, Willardson searched for a picture of two kids on a beach towel with an American flag design using a picture of a flag found online. The demo machine took only a couple of seconds to find hundreds of matching images from a photo library.