How does Super Pi work?

I'm trying to use Super Pi to measure the speed of my laptop, however after i'll installed it, it asks me about something like 138, 512, 1mb and stuff like that. Which one am I suppose to select?

 

Each option is the number of integers the program will count pi:

64K will calculate pi out to 64,000 digits

128K to 128,000 digits

1m to 1 million digits

you get the idea.

The purpose is just to see how long it will take your processor to do this.

The only way this seems to be usefull to me is to compare it to other numbers which will usually say either 1 million or 2 million etc.

Hope this helps

 

we always use the 2M (2-million digits of accuracy) calculation for notebooks on this site, although as processors get faster and faster we'll probably move to calculating 4M.

And as a math refresher, remember the formula for circumference of a circle = 2 * Pi * Radius (or Pi * Diameter) and therefore Pi = Circumference / Diameter, in other words the Circumference of a circle is always the same ratio to the diameter no matter what the circle's size, Pi is an irrational number though and its digits go on forever -- we'll never know it's true exact value, but we can calculate out a bunch of decimal spaces just for fun and to test a processor!

 

One day in the future we'll look back and say:
"I can't believe those idiots couldnt' calculate pi"

 

I read that the algorithm was propriatory.

 

Thank you all for your replies.

The result I got from doing a 2M test was 1m 42secs, is this ok? or is this a bad figure?

 

That seems fine.

What is your processor?

 

Umm... I think its Pentium M Centrino? 1.73

Sorry I'm not good with stuff like this. Hope you know what I'm talking about

 

Yes that's what you have. 1.73GHz, second generation (533FSB)

That's the range that you should be in. That's on par with my P4 3.2GHz

 

looking back at the review of the N3510 that we had here on the site. At the time it scored 1:48. So you actually managed a better time

http://www.notebookreview.com/default.asp?newsID=2322

 

My P-M 1.86 scores around a 1:41. you might have the 1.86 instead. or just an abnormally fast 1.73

 

It's definitely a 1.73, those are the numbers I got after I've ran the test.
Would the amount of ram affect the figures?

 

No it's not abnormally fast. Neither is yours abnormally slow. There's just a rather wide range of expected results, due to the differences in the environments.

 

My PM1.73 got 1:41 for the 2M digits. My desktop AMD 64 3200+ go 1:41. When it's overcloced from 2ghz to 2.2ghz it does 1:29. Your super pi time depends on how many processes you have running in the background. For example when I disable my Antivirus I get 1 second less.

 

Yes it would. In the beginning of the CPU speed thread there were fierce arguments about this but the results show that one and the same CPU with different amount of RAM will give different results.

 

Mine ran a 1:13 first time around *whistles*

 

going from 512 to 1GB only dropped my time by about a second, within the range of error between tests.

 

Going from 512MB to 1GB made it slower for me. By 2-3 seconds at most, but still.