Parallel Prime95 code and instructions

[T.Rex]

OK. I spent nearly 1/2 an hour searching for code and instructions for the parallelized version of Prime95. (I was away from the forum for too long, so I'm lost now.)

Better to ask:
Where can I find all the code and instructions about the parallel version of Prime95 ?
- executable file
- source code
- instructions for compiling the code
- instructions for saying Prime95 to run in // on several cores

(I have access to a Nehalem 8 cores....)

Thanks,
Tony

[ixfd64]

The 8-core "Nehalem" chip isn't supposed to be out until late 2009. Does Bull have connections with Intel or something?

[Cruelty]

Sound more like 2-way 4-core system
Besides Nehalem chips will have hyperthreading enabled so 4-core system means 8 threads.

[ixfd64]

That makes more sense, but still, none of the "Nehalem" chips have been released yet.

[Cruelty]

Yes, but several people already are using engineering samples...

[Mini-Geek]

Links to executables can be found at http://www.mersenneforum.org/showthread.php?t=9779

Not 100% sure, but this link looks promising for the source:
ftp://mersenne.org/gimps/source256.zip
Not sure about compiling.

For the settings to run 1 number across the 8 cores, go to Test > Worker Threads and set as follows:

Number of worker threads: 1
Number of CPUs to use: 8
The other settings can be set to whatever you want, depending on what you want to do (obviously).

[ATH]

Originally Posted by T.Rex

(I have access to a Nehalem 8 cores....)

Is it 8 real cores? Then it would be 16 threads. I read that Nehalem reintroduces hyperthreading, so a quad core would have 8 threads.

[T.Rex]

Originally Posted by ATH

Is it 8 real cores? Then it would be 16 threads. I read that Nehalem reintroduces hyperthreading, so a quad core would have 8 threads.

It is a proto Nehalem, with 8 cores I've been said (not played with it yet). So performances should not be the top of what is expected next year. End I do not want to use HyperThreading. Yes, Bull has a cooperation contract with Intel (and I think I have to check what I'm authorized to say about perf of Nehalem...).
Tony

[T.Rex]

Originally Posted by Mini-Geek

For the settings to run 1 number across the 8 cores, go to Test > Worker Threads and set as follows:

Number of worker threads: 1
Number of CPUs to use: 8

The version I'm using:

Linux,Prime95,v25.6,build 6

Where is described the format of the worktodo.txt file ?
mprime refuses the old format.

[Main thread Sep 11 06:51] Mersenne number primality test program version 25.6
[Main thread Sep 11 06:51] Error: Worktodo.txt file contained bad LL exponent: 0
[Main thread Sep 11 06:51] Illegal line in worktodo.txt file: Test=M43xxxxxx,68,1

T.

[T.Rex]

Originally Posted by Mini-Geek

Number of worker threads: 1
Number of CPUs to use: 8

OK ! Thanks. On my small machine, it adds the following in local.txt:

ThreadsPerTest=2
WorkerThreads=1

Tony

[T.Rex]

Originally Posted by T.Rex

mprime refuses the old format.

[Main thread Sep 11 06:51] Illegal line in worktodo.txt file: Test=M43xxxxxx,68,1

T.

OK! Simply remove the "M" !!
Test=43xxxxxx,68,1
No ascendant compatibiliy between versions...
T.