On Mon, Dec 14, 2020 at 12:54:27PM -0800, Yasha Karant wrote:
> ... Out of curiosity, how similar are the Apple Mac ARM CPUs to the CPU used in
> the Fujitsu Fugaku HPC machine (A64FX 48C 2.2GHz)?

Hard to tell. (easy to tell, "just read the specs")

The Intel "magic souce" was always the "cache + memory controller" combo that
consistently runs a few cycles faster compared to competition (IBM, SGI, AMD, Altera,
Xilinx, etc), and people see this difference in real-world applications.

How good is the generic ARM cache and memory controller and the Apple cache and memory controller,
and in real world applications, remains to be seen. As of a few years ago (1 GHz era), ARM chips
built for embedded use had pretty slow memory (i.e. single channel vs Intel dual/quad channel,
DDR3-1066 vs DDR4-3200, that kind of slow). Today's ARM? I guess I should run my memory benchmarks
on my RPi3/RPi4 boards and on the latest Xilinx ARM board we have in the lab...

And then there are the "performance/$$$", "performance/watt" and "performance/kg" metrics.

ARM always did well in "performance/watt", meaning that you can cram more of them
in the same cooling-limited volume, yielding good "performance/m^3", important for building
supercomputers.

-- 
Konstantin Olchanski
Data Acquisition Systems: The Bytes Must Flow!
Email: olchansk-at-triumf-dot-ca
Snail mail: 4004 Wesbrook Mall, TRIUMF, Vancouver, B.C., V6T 2A3, Canada