Computer chips become more complex over time. We know this in our bones by now, in various ways, whether it’s watching ever more functionality get crammed into smart phones or the constant drumbeat being sounded for, well, the constant drumbeat of Moore’s Law. In recent years, we’ve watched the CPU rise from a single core to two, four, and even more. Cache sizes, clock speeds, and performance have grown over time, as well.
Even so, the sheer scope of AMD’s new processor—code-named “Llano” and creatively dubbed an “accelerated processing unit” (APU) rather than a CPU—may cause you to do a double-take. This one chip incorporates a whole host of elements, many of which used to reside in other parts of a PC: up to four traditional CPU cores, a north bridge, a DDR3 memory controller, a bundle of PCI Express connectivity, a moderately robust Radeon GPU with an associated UVD block for video acceleration, and a pair of display interfaces. That’s a mighty long list of capabilities consolidated into one piece of silicon, almost a system on a chip rather than a CPU surrounded by many helpers.
By integrating so many pieces together, Llano follows a trajectory for CPUs established long ago, when they first incorporated floating-point units. L2 caches were next to be assimilated, followed by memory controllers in AMD’s K8. The integration trend has really picked up steam in recent years, though, and the most fully realized example has been Llano’s primary competitor, Intel’s Sandy Bridge processor. Even though it follows Sandy Bridge by roughly half a year, Llano still feels like a notable milestone on the integration path, in part because AMD has covered a lot of ground in this single step—and in part because Llano has absorbed a familiar and relatively formidable Radeon GPU.
http://techreport.com/articles.x/21099
