Review your favorite Linux distribution.
Go Back > Forums > Linux Forums > Linux - Server
User Name
Linux - Server This forum is for the discussion of Linux Software used in a server related context.


  Search this Thread
Old 12-07-2017, 06:40 AM   #1
LQ Newbie
Registered: Dec 2017
Posts: 1

Rep: Reputation: Disabled
drastic reduction in performance when compute node running at half load

We have compute nodes with 24 cores( 48 threads) and 64 GB RAM (2x32GB). When I run a sample code (matrix multiplication)in one of the compute node in one thread, it takes only 4 seconds. But when I starting more runs (copy of the same program) in the same compute node, the time taken increases drastically. When the number of programs running reaches 24 (I gave maximum 24 since physically only 24 cores are present), the time taken becomes like around 40 seconds ( 10 times less). When I checked the temperature, it is below 40 deg Celsius.

When I searched in the Internet about this issue, I found some people saying that it may be due to slowing down of transfer of data from ram to processor when we run many programs. I was not satisfied with this comment, because the compute nodes are designed to run at maximum load with out much decrease in performance. Also, we are using only 1GB of memory even with 24 programs running. Since we are getting performance reduction of about 1/10, I guess the problem is something else.
Old 12-11-2017, 01:59 AM   #2
LQ Guru
Registered: Mar 2012
Location: Hungary
Distribution: debian/ubuntu/suse ...
Posts: 11,606

Rep: Reputation: 3494Reputation: 3494Reputation: 3494Reputation: 3494Reputation: 3494Reputation: 3494Reputation: 3494Reputation: 3494Reputation: 3494Reputation: 3494Reputation: 3494
but you gave no usable information and therefore we can only shoot in the dark. You may need to check other resources, like disk i/o, swap usage and others, probably you will find something. Is this a multithreaded app? Which language was used ....


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
LXer: Set up Two Node RDO Juno ML2&OVS&VXLAN Cluster runnig Docker Hypervisor on Compute Node LXer Syndicated Linux News 0 02-07-2015 08:31 AM
[SOLVED] Rocks does not see any compute node Sefid par Linux - Server 2 12-28-2014 11:37 AM
Why is my Kickstart file not being received by my compute node? NPESlayer ROCK 2 10-28-2014 10:42 AM
Trying to bring up first compute node brownwrap ROCK 0 01-31-2014 06:45 PM
[SOLVED] activating second NIC on unicluster compute node daisychick Linux - Networking 3 01-31-2012 11:21 PM > Forums > Linux Forums > Linux - Server

All times are GMT -5. The time now is 04:10 AM.

Main Menu
Write for LQ is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration