Previous | Next --- Slide 12 of 34
Back to Lecture Thumbnails

Note that the crossbar is about the size of a core, and that all of the caches lie between it and the the cache's core.


Oracle reports the bandwidth of the crossbar tops to 180GB/s, while Core-i7's QPI is around 10-20 GB/s. It seems full crossbar does offer a incredible performance boost.


Still, even with great performance gains, you loose a whole lot of the dye to just the interconnect.


@ToBeContinued. You're comparing inter-chip communication via QPI to inter-core communication on the same chip via the T2 crossbar. That's not a fair comparison. A more fair comparison would be to compare the crossbar's bandwidth to the ring bus bandwidth on a modern Intel CPU.