AMD released Threadripper CPUs in 2017 [soylentnews.org], built on the same 14nm Zen architecture as Ryzen, but with up to 16 cores and 32 threads. Threadripper was widely believed to have pushed Intel to respond with the release of enthusiast-class Skylake-X chips [soylentnews.org] with up to 18 cores. AMD also released Epyc-branded server chips [soylentnews.org] with up to 32 cores.
This week at Computex 2018, Intel showed off a 28-core CPU [tomshardware.com] intended for enthusiasts and high end desktop users. While the part was overclocked to 5 GHz, it required a one-horsepower water chiller to do so [tomshardware.com]. The demonstration seemed to be timed to steal the thunder from AMD's own news.
Now, AMD has announced two Threadripper 2 CPUs [anandtech.com]: one with 24 cores, and another with 32 cores. They use the "12nm LP" GlobalFoundries process [soylentnews.org] instead of "14nm", which could improve performance, but are currently clocked lower than previous Threadripper parts. The TDP has been pushed up to 250 W from the 180 W TDP of Threadripper 1950X. Although these new chips match the core counts of top Epyc CPUs, there are some differences:
At the AMD press event at Computex, it was revealed that these new processors would have up to 32 cores in total, mirroring the 32-core versions of EPYC. On EPYC, those processors have four active dies, with eight active cores on each die (four for each CCX). On EPYC however, there are eight memory channels, and AMD's X399 platform only has support for four channels. For the first generation this meant that each of the two active die would have two memory channels attached – in the second generation Threadripper this is still the case: the two now 'active' parts of the chip do not have direct memory access.
This also means that the number of PCIe lanes remains at 64 for Threadripper 2, rather than the 128 of Epyc.
Threadripper 1 had a "game mode" [anandtech.com] that disabled one of the two active dies, so it will be interesting to see if users of the new chips will be forced to disable even more cores in some scenarios.