Calculation of pi on many machines

[Benoit Maag]

Bob,

To answer some of your questions:

a. The comparison is not quite apples to apples. For most of the machines (including the HP-67), the data is stored as #####.##### (5 + 5 digits) and the calculation is performed on 5 digits at a time. This means each registered has to be split into 5 digits which are processed separately. But this is not possible on the HP-65 because there is not enough program memory and no indirect addressing. So the data is stored as 0.####### (7 digits), there is no need to split registers and this is why it is faster than the HP-67. It would be interesting to see how the 67 performs with the 65 program

c. I was surprised by the Casio as well, especially the fox-6300G which is a cheap machine. I think the speed is attributable to the very simple programming language

d. The DM42 is super fast because the data is stored as 17+17 digits and all calculations are made 17 digits at a time. I have not checked the performance with a 5+5 digit program. BTW, for the WP 34S, I tested both 5+5 and 8+8 digit data

e. I am not sure why the slopes would be different. After all, the time is proportional to the square of the number of desired digits so all curves should be parallel

More to come as I would like to run the benchmark on the 32sii, 35s, RPL machines, BASIC sharps and casios, NumWorks (python), TI-58, and maybe the RPN-1250 I presented at HHC 2018, though it is not a bcd machine and has poor calculation precision

(11-22-2020 10:50 PM)rprosperi Wrote:  Thanks for all your time doing the testing, documenting it all and sharing it here Benoit.

There's LOTS of real useful and interesting stuff just in the chart alone. Among them:

a. the 65 is faster the 67
b. the 41 is only a tad faster than the earlier machines and the 29 is faster still
c. the surprisingly high performance of the early Casio machines
d. the amazing speed of the DM42
e. the quite different slope of the 65 and 29 (gotta go read that in detail)

Looking forward to reading it in more detail.

Thanks!