Pi Day


8 posts
by bryanandaimee » Fri Mar 14, 2014 3:49 am
I figured I ought to do something with the Pi for Pi day (3/14) so i installed Pi on my Pi,

sudo apt-get install pi

then i calculated Pi on the Pi to 3.141593 (rounded) million decimal places.

pi 3141593 > pimil.txt

The calculation took 132 seconds on my old Pi (256 MB version B) running at 1100 Mhz arm, 500 ram, and 500 core.

If you were to run a heavily overclocked Pi all day (on Pi day) calculating Pi, I think you could probably get close to calculating Pi-billion decimal places of Pi but I'm not sure if Pi would calculate that many digits of Pi on the Pi due to memory size constraints.

Bryan
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by Douglas6 » Fri Mar 14, 2014 4:06 am
Makes me think of that distributed SETI project. With 2.5 million Pis, we should have found ET by now.
If they weren't busy mining bitcoins, I guess.
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by bryanandaimee » Fri Mar 14, 2014 2:14 pm
How many digits per day could a beowulf cluster of 314 Pi's calculate? The world may never know.

Turns out that my Pi runs out of memory after only 20 minutes or so and kills the process. So the max number of digits I can calculate is something like 20 million. The 512 MB Pi's could probably do quite a bit better.

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by lazarus78 » Fri Mar 14, 2014 6:25 pm
Douglas6 wrote:Makes me think of that distributed SETI project. With 2.5 million Pis, we should have found ET by now.
If they weren't busy mining bitcoins, I guess.

The Pis are actually very very VERY terrible for mining any type of cryptocoin, let alone bitcoin. It is literally a waste of power to even attempt it.

If you are talking about people who spend thousands of dollars on 6 GPU systems for mining, then yes, that is indeed also a waste of effort.
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by pluggy » Fri Mar 14, 2014 6:34 pm
Its getting to be a waste of money using dedicated ASICs to mine Bitcoin nowadays. It a lot cheaper to just buy it....

Ebay is awash with S/H Bitcoin ASICs at knock down rates.
Don't judge Linux by the Pi.......
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by DougieLawson » Fri Mar 14, 2014 6:37 pm
pluggy wrote:Its getting to be a waste of money using dedicated ASICs to mine Bitcoin nowadays. It a lot cheaper to just buy it....

Ebay is awash with S/H Bitcoin ASICs at knock down rates.

Is it?

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by pluggy » Fri Mar 14, 2014 6:44 pm
Cheap power, if you watch the video. Its not viable at consumer power prices.
Don't judge Linux by the Pi.......
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by bryanandaimee » Sat Jul 26, 2014 12:26 am
Just found a post on Mathematica about calculating pi and it looks like that speeds things up quite a bit.
Code below:

(*Clear Cache*)
ClearSystemCache[]

(*Calculate pi to 1 million decimal places and store the result*)
AbsoluteTiming[pi = N[Pi, 1000000];]


On the same setup as before I got:
pi million decimal places 38.4 seconds
2pi million decimal places 93.8 seconds
4pi million dp 241.4 seconds

Same memory limits seem to apply. Limit is somewhere around 20 million dp
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