20170523, 03:37  #1 
"/X\(‘‘)/X\"
Jan 2013
3·977 Posts 
Best approach for P1?
My computer cluster is loaded with memory that I'm not taking advantage of. I understand P1 can use the memory, but I'm unsure where to start with configuring things optimally.
Each node has 4 cores and 32 GB of memory with good memory bandwidth. I'm currently using a single worker for LL/DC. Suggestions? 
20170523, 04:38  #2 
Sep 2006
Brussels, Belgium
2×5×167 Posts 
Use two workers : one for LL work and the other for P1. On the machine where I do this, I assigned two cores to each worker. By running just one P1 worker you avoid the problem of having two workers competing for high memory usage during stage 2.
Jacob 
20170523, 12:32  #3 
"Kieren"
Jul 2011
In My Own Galaxy!
2×3×1,693 Posts 
IIRC, my experience was that Stage 1, P1 makes use of 2 cores fairly well. Stage 2 seemed to use 1.5 to 1.7 cores out of 2. Perhaps this reflects lack of memory bandwidth on the machines I was using?

20170523, 14:53  #4 
"/X\(‘‘)/X\"
Jan 2013
B73_{16} Posts 
So maybe I should allocate 3 cores to an LL worker and 1 to a P1 worker?
I'll have to do some benchmarking. 
20170523, 17:27  #5  
"Kieren"
Jul 2011
In My Own Galaxy!
2·3·1,693 Posts 
Quote:
6700K @ 4.3 GHz, Kingston dualrank 8 GB x 2, rated 2666, running @ 3200 A quick search of results.txt suggests that core completed an 81.5M assignment in 1214 hours. The 3 core DCLL took 5760 hr, v 2425 hr for all four cores. Last fiddled with by kladner on 20170523 at 17:43 

20170523, 19:15  #6  
"/X\(‘‘)/X\"
Jan 2013
3×977 Posts 
Quote:


20170523, 23:58  #7 
"Kieren"
Jul 2011
In My Own Galaxy!
2·3·1,693 Posts 
I should probably verify that on additional exponents. With only two samples, both could have included down periods with no output.
Last fiddled with by kladner on 20170523 at 23:58 Reason: , 
Thread Tools  
Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Unorthodox approach to primes  Erkan  PrimeNet  7  20170110 03:34 
An Analytic Approach to Subexponential Factoring  akruppa  Math  2  20091211 18:05 
Best approach for 130 digits?  boothby  Factoring  10  20091016 17:24 
Factoring with the birthday problem approach  ThiloHarich  Factoring  0  20090818 16:48 
The binary multiply convolution approach  Dresdenboy  Math  4  20030602 17:23 