Parallel Prime95 code and instructions
 

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:
[B]Where can I find all the code and instructions about the parallel version of Prime95 ?[/B]
- 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

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

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

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

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

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

Not 100% sure, but this link looks promising for the source:
[URL]ftp://mersenne.org/gimps/source256.zip[/URL]
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).

[QUOTE=T.Rex;141921](I have access to a Nehalem 8 cores....)[/QUOTE]

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.

[QUOTE=ATH;141932]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.[/QUOTE]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

[QUOTE=Mini-Geek;141929]
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
[/QUOTE]
The version I'm using:
[CODE]Linux,Prime95,v25.6,build 6[/CODE]

Where is described the format of the worktodo.txt file ?
mprime refuses the old format.
[CODE][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[/CODE]

T.

[QUOTE=Mini-Geek;141929]
Number of worker threads: 1
Number of CPUs to use: 8
[/QUOTE]OK ! Thanks. On my small machine, it adds the following in local.txt:
[CODE]ThreadsPerTest=2
WorkerThreads=1[/CODE]
Tony

[QUOTE=T.Rex;141942]mprime refuses the old format.
[CODE]
[Main thread Sep 11 06:51] Illegal line in worktodo.txt file: Test=M43xxxxxx,68,1[/CODE]

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

Here's an example of a new worktodo.txt (I don't know of some full documentation about the new format, but the only big difference is the Worker #1 line):[code][Worker #1]
Test=43000019,68,1[/code]Besides the Worker #1 line, I notice it shows you put an M in front of the number. Edit: Oh, the only problem was the M. I guess the worker lines are only necessary to differentiate with multiple workers, and is not necessary for a single worker thread.

Is your small machine a dual core? I expect it'd change the number of CPUs to use to your number of CPUs if you enter a number higher than your number of CPUs (if that makes any sense :smile:).

Adding work to v95.6
 

perhaps this post will help
[URL]http://www.mersenneforum.org/newreply.php?do=newreply&p=137277[/URL]

You may also want to look at some other posts in the thread rather tedious I admit. Also works for other types of work.

nelson

Thanks for your help !
 

Thanks for your help, guys ! I've understood.
I'll add some post in the "Perpetual Benchmark" Thread soon.
Tony

What about posting the

cat /proc/cpuinfo

output ... there you can see what features you do have (real cores or hyperthreaded).