Today I ran 2750 iterations of the matrix on some additional machines.
My 64GB iPad 3 runs a 1 GHz, dual-core, 32-bit, ARM Cortex-A9 and ran the test in 1.308 seconds on load and about 1.15 seconds on rerun.
My MacBook Pro from 2013 runs a 2.7 GHz Core i7 and did the initial run in 0.09-0.130 seconds and re-runs in as little as 0.070 seconds. That’s almost as fast as my 2015 notebook PC.
I wasn’t kidding about digging up my old Palm Pre, either. I finally got it charged up and running but found it would only run up to 500 iterations before it would hang. I therefore created another version of the test which runs only 500 iterations, as shown below.