GIMPS uses only 1 cpu

Hi, I have an Amd X2 5600+ and prime95 uses only one of the 2 core of my cpu. I couldn't find how to make it work. If I put 2 workers threads in the options the programm replies "you have allocated more threads than CPUs avalaible, this is likely to reduce performance. Why is that ? Can't I use the 2 cores to compute 2 tests at the same time ?
Thx

Weird, what O.S. are you using???????

[joblack]

Originally Posted by Unregistered

Hi, I have an Amd X2 5600+ and prime95 uses only one of the 2 core of my cpu. I couldn't find how to make it work. If I put 2 workers threads in the options the programm replies "you have allocated more threads than CPUs avalaible, this is likely to reduce performance. Why is that ? Can't I use the 2 cores to compute 2 tests at the same time ?
Thx

The configuration is a little bit counterintuitive (hello prime95 ;) ...

You set the number of worker windows to 2 and now you have to set up every workers cpu manually with 1 (so the sum is two). For all workers you can´t set it up in that case (doesn´t work in v29 - perhaps a bug).

If you´re sure that you have two cores you and you have checked that ever worker has only one cpu you can ignore this message ... strange anyway.

Have you tried the newest prime95 v29beta?

I'm using windows xp. Prime95 now uses the 2 cpus but only for testing one prime number. It would be more interesting to run 2 tests in parallel, as the speed is increased by only 40% when i'm using two cores for the same number. I have only one test in queue. I was using prime v24 and i didn't get another prime to compute for my second core. What do I have to do to get another test thus using one core for on prime ?

Also download links dont work, so is the mirror.

[joblack]

Originally Posted by Unregistered

I'm using windows xp. Prime95 now uses the 2 cpus but only for testing one prime number. It would be more interesting to run 2 tests in parallel, as the speed is increased by only 40% when i'm using two cores for the same number. I have only one test in queue. I was using prime v24 and i didn't get another prime to compute for my second core. What do I have to do to get another test thus using one core for on prime ?

If the 'number of worker windows' is set to one (but the #cpu to 2) you use one worker thread with two cpu threads. If you set it to 2 (and give every worker thread one cpu) you use two worker threads with one cpu.

Normally you give every worker thread only one cpu, but if you want to get the higher numbers (for instance if you want to be the first to find a 100M) people are assigning more cpus to one worker thread.

[Uncwilly]

Originally Posted by Unregistered

Also download links dont work, so is the mirror.

From http://www.mersenne.org/freesoft.htm I downloaded v25.8 today. So it should be working.

[starrynte]

depending on how you want to do it:
if you want ONE worker utilizing BOTH cpu's, then set 1 worker window and multithreading 2
if you want TWO workers each running on ONE cpu, then set 2 worker window and with "all workers" selected, multithreading 1