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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 ne

by leeter 6y ago

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 6y ago
The "traditional CPU" portion of the core is a bit more capable than KNL, but yeah, that's roughly accurate.
- leeter 6y ago
  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.
gnufx 6y ago
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 6y ago
  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/Xeon_Phi https://en.wikipedia.org/wiki/Larrabee_(microarchitecture) https://en.wikipedia.org/wiki/Larrabee_(microarchitecture)
  - gnufx 6y ago
    Sure, but people don't normally think of "GPU" in this context as just runs all your x86_64 code.
m_mueller 6y ago
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).

by leeter 6y ago

stephencanon 6y ago

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

leeter 6y ago
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.

gnufx 6y ago

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 6y ago
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/Xeon_Phi https://en.wikipedia.org/wiki/Larrabee_(microarchitecture) https://en.wikipedia.org/wiki/Larrabee_(microarchitecture)
- gnufx 6y ago
  Sure, but people don't normally think of "GPU" in this context as just runs all your x86_64 code.

m_mueller 6y ago

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).