[leeter]

So looking at anandtech's breakdown the CPUs are closer to a knights landing 'CPU/GPU' than a traditional CPU (currently). They also have a ton of HBM2 right next to the dies so this should be insanely fast as they can feed those cores very very quickly regardless of how fast each core is by clock and pipeline. That should massively reduce stalls.

[stephencanon]

The "traditional CPU" portion of the core is a bit more capable than KNL, but yeah, that's roughly accurate.

[leeter]

Oh agreed, but honestly what makes this so interesting is how tuned it is. I'm honestly surprised we haven't seen Intel or AMD ship an HPC CPU with on package HBM2 yet.

[m_mueller]

Besides FLOP/Watt what's also very interesting here is the FLOP/Byte ratio (memory bandwidth). It has kept the same balance as K computer, i.e. is geared at scientific workloads and not just benchmarks (duh, just worth pointing out here as it makes this machine quite special especially compared to Xeon based clusters - Intel IMO has dropped the ball on bandwidth since the last 5 years or so).

[gnufx]

As an early user of KNL, I don't get the "GPU" bit. KNL runs normal x86_64 code and doesn't look that much different to the AMD Interlagos systems I once used apart from the memory architecture.

[leeter]

It comes from the fact that KNL came from Larrabee which was actually developed as a GPU initially (and even ran games... sort of) but was never actually released. The next revision of that was the Xeon Phi chips you used. So the connection is "Lots of small cores with lots of high bandwidth ram" although these cores are definitely superscalar where Larrabee and derivatives were not really.

https://en.wikipedia.org/wiki/Xeon_Phi https://en.wikipedia.org/wiki/Larrabee_(microarchitecture)

[gnufx]

Sure, but people don't normally think of "GPU" in this context as just runs all your x86_64 code.