Fregmentation and too much RAM requirement
Posted: Mon Sep 09, 2019 12:19 pm
Dear Developers,
I'm facing a memory issue (RAM) while doing BSE calculations even for Si. I have found some useful stuff in the forum before posting the question but could not get to the point answer to my situation.
What I have is a machine with 48 threads and 125GB total RAM while more than 10 TB of HDD available. Now after doing convergence tests for Si system I run the final calculation with converged parameters. But it stopped, probably due to insufficient RAM! I'm attaching BSE input and report file in the attachment.
Q1: What I was looking for to find the possibility to write BS matrix to HDD (as I have plenty of storage) instead of RAM or somehow reduce the RAM requirement.
Moreover, I am also not familiar with parallelization in BSE. I don't mention these lines of code in my input
instead, I just run via,
Q2: Is this way of submitting the job demands more RAM etc?
Now I have also added a new line (added later) to fragment the wfs to see if it helps by introducing,
And finally, I want to know about damping (this is not directly relevant to this thread but then I will have to ask it again!)
Q3: If I increase the damping range will it make the width of the peaks broader or make them narrower? And can't we apply this broadening to specific peaks only to mimic the experimental curve closely?
Regards,
Haseeb Ahmad
MS - Physics
LUMS, Pakistan.
I'm facing a memory issue (RAM) while doing BSE calculations even for Si. I have found some useful stuff in the forum before posting the question but could not get to the point answer to my situation.
What I have is a machine with 48 threads and 125GB total RAM while more than 10 TB of HDD available. Now after doing convergence tests for Si system I run the final calculation with converged parameters. But it stopped, probably due to insufficient RAM! I'm attaching BSE input and report file in the attachment.
Q1: What I was looking for to find the possibility to write BS matrix to HDD (as I have plenty of storage) instead of RAM or somehow reduce the RAM requirement.
Moreover, I am also not familiar with parallelization in BSE. I don't mention these lines of code in my input
Code: Select all
BS_CPU= "-- -- --" # [PARALLEL] CPUs for each role
BS_ROLEs= "k eh t" # [PARALLEL] CPUs roles (k,eh,t)
BS_nCPU_invert= 4 # [PARALLEL] CPUs for matrix inversion
BS_nCPU_diago= 4 # [PARALLEL] CPUs for matrix diagonalization
Code: Select all
export OMP_NUM_THREADS=4
nohup mpirun -np 20 yambo -F file name -J prefix & disown
Now I have also added a new line (added later) to fragment the wfs to see if it helps by introducing,
Code: Select all
DBsFRAGpm= "+BS"
Code: Select all
% BDmRange
0.10000 | 0.10000 | eV # [BSS] Damping range
%
Regards,
Haseeb Ahmad
MS - Physics
LUMS, Pakistan.