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Old 2009-11-25, 16:49   #1
TheJudger's Avatar
Mar 2005

2·3·5·37 Posts
plus mfaktc: a CUDA program for Mersenne prefactoring

[edit by LaurV]

As the thread got longer and longer and people continue coming and asking "Where is this or that version of mfaktc?" I am editing this post to give the link to the folder which Xyzzy kindly created:

Here you can find many different versions of mfaktc, for different OS-es, different Cuda drivers, bla bla.
Select the suitable one for you, download it, clear some exponents!

[end of edit by LaurV]


maybe a bit offtopic...

as a proof-of-concept I can do TF on my GTX 275 :)
A straight forward implementation of the multiprecision arithmetic gives me ~15.000.000 tested factors per second for a 26bit exponent and factors up to 71bit. (The numbers are out of my mind, I hope they are correct)
I've checked the correctness for some 1000 cases against a basic implementation using libgmp on CPU, no errors found. :)

Currently there is no presieving of factor candidates... but I've alot cycles free on the CPU. ;)

The quality of the code right now is.... "proof-of-concept" (means really ugly, alot of hardcoded stuff, ...) :D

Most time is spent on the calculation if the reminder (using a simple basecase division).
jasonp: if you read this: the montgomery multiplication suggested on the nvidia forum doesn't look suitable on CUDA for me. :(


Last fiddled with by LaurV on 2012-12-28 at 06:12
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