# CMAQ5.3.1 Multi-node run fails
**URL:** https://forum.cmascenter.org/t/cmaq5-3-1-multi-node-run-fails/4118
**Category:** CMAQ
**Created:** [May 16, 2023, 3:38pm UTC](https://forum.cmascenter.org/t/cmaq5-3-1-multi-node-run-fails/4118 "2023-05-16T15:38:27Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Axueaha](https://forum.cmascenter.org/u/Axueaha)
#### Post date: [May 16, 2023, 3:38pm UTC](https://forum.cmascenter.org/t/cmaq5-3-1-multi-node-run-fails/4118/1 "2023-05-16T15:38:27Z")
Hi, I’m using cmaq5.3.1, bisheng compiler. The grid resolution is 27km, 182\*138. When I run cctm script, it can only run on single processor, but not on two or more nodes. Is it a compilation problem or a setting in the script, can someone help me? I uploaded the log file and script. Thanks a lot.
[buff\_CMAQ\_CCTMv531\_wangn\_20230516\_152624\_607101675.txt](https://forum.cmascenter.org/uploads/short-url/6INDcZxhBv0MEFu0XdGoQqU44Pi.txt) (17.1 KB)
[config\_cmaq.txt](https://forum.cmascenter.org/uploads/short-url/mkYGLFSWsEk8HdeuU2GA8xmNR4G.txt) (11.3 KB)
[run\_cctm.txt](https://forum.cmascenter.org/uploads/short-url/o26uKK6ASWe9vXiosdXp8bVntbt.txt) (35.0 KB)
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### Author:  [@lizadams](https://forum.cmascenter.org/u/lizadams)
#### Post date: [May 19, 2023, 4:27pm UTC](https://forum.cmascenter.org/t/cmaq5-3-1-multi-node-run-fails/4118/2 "2023-05-19T16:27:24Z")
Based on your buff\_CMAQ\*.txt file, you were able to run CMAQ using 120 processors:
/usr/bin/time -p mpirun -N 120 /USERDATA/research/wangn/ffyu/cmaq5.3.1/CCTM\_TEST/scripts/BLD\_CCTM\_v531\_bisheng/CCTM\_v531.exe
In the run\_cctm.txt file,
#DSUB -N 5
#DSUB -R “cpu=128;mem=256000”
Perhaps you were trying to request 5 nodes, or to use 128x5 processors?
It may be advisable to only use 120 out of the 128 processors per node.
In the CMAQ run script this setting determines how many processors the model will use.
@ NPCOL = 30; @ NPROW = 4
If you want to run on 600 processors or 5 x 120, you would need to change the above setting in the run script to use
@ NPCOL = 30; @ NPROW = 20