# Memory's using limitation

**URL:** <https://community.openpbs.org/t/memorys-using-limitation/4155>\
**Category:** Users/Site Administrators\
**Created:** [July 2, 2025, 3:17am UTC](https://community.openpbs.org/t/memorys-using-limitation/4155 "2025-07-02T03:17:32Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![wakaka](https://avatars.discourse-cdn.com/v4/letter/w/d07c76/32.png) [@wakaka](https://community.openpbs.org/u/wakaka)\
**Post date:** [July 2, 2025, 3:17am UTC](https://community.openpbs.org/t/memorys-using-limitation/4155/1 "2025-07-02T03:17:32Z")

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It’s a part of pbs\_cgroups.json:

 ![image](https://canada1.discourse-cdn.com/flex030/uploads/pbspro/original/1X/41f2d637d423afe045504911aaa5c479ad6421cd.png)  
I don’t know if I understand, does it mean that, if I don’t apply memory explicitly, pbs will limit the memory to use under 256MB?

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<div class="post-metadata">

**Author:** ![adarsh](https://avatars.discourse-cdn.com/v4/letter/a/f07891/32.png) [@adarsh](https://community.openpbs.org/u/adarsh)\
**Post date:** [July 2, 2025, 6:13am UTC](https://community.openpbs.org/t/memorys-using-limitation/4155/2 "2025-07-02T06:13:53Z")

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> [@wakaka](#):
>
> I don’t know if I understand, does it mean that, if I don’t apply memory explicitly, pbs will limit the memory to use under 256MB?

If in case your job does not request any memory when submitting a job via qsub. Then 256MB of memory is assigned to the job by default.  
e.g.:

` qsub -l select=1:ncpus=2 -- /bin/sleep 1000`

Refer: [https://help.altair.com/2024.1.0/PBS%20Professional/PBS2024.1.pdf](https://help.altair.com/2024.1.0/PBS%20Professional/PBS2024.1.pdf)  
Section:  
6.5.3.9.iii Assigning a Default Amount of Memory to Jobs  
6.5.3.9.ix memory Subsystem Configuration Parameters