On Monday at the Hot Chips conference, Intel shared the first details of the Beckton processor, which is now called Nehalem EX. (Gotta love those crazy Intel naming conventions—Lynnfield, Beckton, Clarksview. They sound like gated communities in hell.)
The 8-core, 2.3-billion transistor Nehalem EX debuted in a pretty white dress and 18-button white gloves. Charlie Demerjian (formerly with bright red web site The Inquirer, but who has recently started up his own SemiAccurate) has the roundup of what makes Becton interesting: “On the surface, Becton looks like a simple mashing together of two 4-core Nehalems. The specs are 8 cores, 16 threads, 4 DDR3 memory channels, 4 QPI links and 24MB of L3 cache all stuffed into a mere 2.3 billion transistors.”
“With 4 QPI links, 8 memory channels, 8 cores, 8 cache slices, 2 memory controllers, 2 cache agents, 2 home agents and a pony, this chip is getting quite complex… To make it all work, the center of the chip has a block called the router. It is a crossbar switch that connects all internal and external channels, up to eight at a time.
With that many available inputs and outputs, you start to understand why the focus of Becton was on the uncore, and how things get moved around the die and the system in general. Without all the effort put in, just doubling up a Bloomfield or Lynnfield wouldn't scale at all, much less to the 2,000-plus cores Intel is claiming Becton will hit.”
Leaving aside for the moment the hair-raising projection of 2000 cores—let’s discuss the uncore.
Because, with the terms multicore and manycore shoved firmly down marketers’ throats, it’s time for a new buzzword: Uncore. That’s right, uncore: a term so new, its Wikipedia page doesn’t even have references. (disclaimer for anyone who is going to burst into tears of didactic rage telling me the term is not new: that was dry, sardonic humor.)
The uncore is just everything on a microprocessor that is not the core: the arithmetic logic unit, floating point unit, and cache.
For reasons that make me sleepy, the uncore must run at twice the memory frequency. But the rest of the Hot Chips conference was much more multicore than uncore.