On Jul 10, 2013, at 11:47 AM, Bradley Lucier <lucier@math.purdue.edu> wrote:

On 06/12/2013 01:07 PM, Bradley Lucier wrote:

Just for laughs and giggles, I decided to calculate 1,000,000,000 (yes, 9 zeros) digits of pi using Bakul Shah's Scheme program implementing the Chudnovsky algorithm. The computation used one CPU core:

model name : Intel(R) Xeon(R) CPU X5570 @ 2.93GHz

with a pretty good memory subsystem with 72GB of memory ...

leibniz-172% gsi chud2
Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 10, CPU time: 0..
Last 5 digits 26535.
Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 100, CPU time: 0..
Last 5 digits 70679.
Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 1000, CPU time: 0..
Last 5 digits 1989.
Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 10000, CPU time: .020000000000000004.
Last 5 digits 75678.
Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 100000, CPU time: .340022.
Last 5 digits 24646.
Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 1000000, CPU time: 5.140321.
Last 5 digits 58151.
Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 10000000, CPU time: 83.765235.
Last 5 digits 55897.
Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 100000000, CPU time: 1327.790981.
Last 5 digits 51592.
Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 1000000000, CPU time: 41907.731069.
Last 5 digits 45519.

This is the same program, run on my new desktop:

model name : Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz

with 16GB of RAM, which seems to run 2-3 times as fast as the server in the math department. (Luckily, a new server will be up and running soon.)

Brad

firefly:~/programs/gambiteer> gsi chud2
Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 10, CPU time: 0..
Last 5 digits 26535.
Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 100, CPU time: 0..
Last 5 digits 70679.
Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 1000, CPU time: 0..
Last 5 digits 1989.
Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 10000, CPU time: .012.
Last 5 digits 75678.
Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 100000, CPU time: .172.
Last 5 digits 24646.
Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 1000000, CPU time: 2.476.
Last 5 digits 58151.
Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 10000000, CPU time: 38.7.
Last 5 digits 55897.
Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 100000000, CPU time: 536.864.
Last 5 digits 51592.
Chudnovsky's algorithm using binary splitting in Gambit Scheme: digits 1000000000, CPU time: 14459.672.
Last 5 digits 45519.