3540 - New computer

As I mentioned the other day I got a new computer that I am trying to get up and running. Not that it doesn't work. It's that I'm trying to figure out HOW it works.

I'd nursed my 2003 Dell Windows XP for as long as I could. But things were starting not to work. I guess I could have just upgraded windows but why do that when you can buy a brand new computer with bells and whistles galore.

I got a Dell i7 6700 with 18 gig of RAM. How fast is it you ask? Well here's a test that I run. It's a program called Pifast. It generates as many digits of pi as you want. When I got my XP computer I set it up to generate 100,000,000 digits of pi and print them to a file.

The XP computer did this...

Program : PiFast version 4.2, by Xavier Gourdon
Computation of 100000000 digits of Pi
Method used : Chudnovsky
Size of FFT : 2048 K
Physical memory used : ~ 99568 K
Disk memory used : ~ 429.15 Meg
------------------------------------------------------------
Computation run information :

Start : Fri Jun 20 01:47:25 2003
End   : Fri Jun 20 02:43:11 2003
Duration : 3345.38 seconds

Time spent in disk swapping : 335 s (reading 122, writing 214)
============================================================
Total computation time : 3345.38 seconds (~ 0.93 hours)
============================================================
Pi with 100000000 digits :
Pi = 3.
1415926535 8979323846 2643383279 5028841971 6939937510  : 50
5820974944 5923078164 0628620899 8628034825 3421170679  : 100
8214808651 3282306647 0938446095 5058223172 5359408128  : 150
4811174502 8410270193 8521105559 6446229489 5493038196  : 200
4428810975 6659334461 2847564823 3786783165 2712019091  : 250
4564856692 3460348610 4543266482 1339360726 0249141273  : 300
7245870066 0631558817 4881520920 9628292540 9171536436  : 350
7892590360 0113305305 4882046652 1384146951 9415116094  : 400
3305727036 5759591953 0921861173 8193261179 3105118548  : 450
0744623799 6274956735 1885752724 8912279381 8301194912  : 500
And on and on and on...

The thing I was looking for was the computation time. As you can see above it was 3345.38 seconds or about 56 minutes. Not bad back in 2003.

My new computer did this...

Program : PiFast version 4.3 (fix 1), by Xavier Gourdon
Computation of 100000000 digits of Pi
Method used : Chudnovsky
Size of FFT : 8192 K
Physical memory used : ~ 525521 K
Disk memory used : ~ 0.00 Meg
------------------------------------------------------------
Computation run information :

Start : Sat Dec 10 14:06:51 2016
End   : Sat Dec 10 14:09:48 2016
Duration : 177.03 seconds
============================================================
Total computation time : 177.03 seconds (~ 0.05 hours)
============================================================

See that? 177.03 seconds. Not quite 3 minutes. About 19 times faster. And you notice it doesn't talk about disk swapping. Ah 18 gig of memory blazing away.

Then I remember back in 2000 I ran a test generating 1 billion digits on an even older computer. How long did that take? 36 hours. I haven't decided to try that on the new computer yet. I think there will be some disk swapping going on when I do try it.