SCC Batch Computing

Introduction

Most of your heavy compute, such as model training is best run as non-interactive batch jobs on the SCC.

Here, we’ll get familiar with the process and commands.

SCC’s batch job system is based on the Sun Grid Engine

References:

https://www.bu.edu/tech/support/research/system-usage/running-jobs/

All the examples here need to be run on an SCC node. A login node is fine.

qsub command

Non-interactive batch jobs are submitted with the qsub command.

Here’s a trivial batch job submission. We’ll just execute the shell printenv command which prints all the environment variables in your shell.

$ qsub -b y printenv
Your job 294013 ("printenv") has been submitted

The -b y option says the command is likely a binary executable, but can also be a script. The submission host won’t try to parse the command as a script and will just pass the path to the command to the execustion node.

qstat command

You can check the status of your job in the queue with

$ qstat -u tgardos
job-ID  prior   name       user         state submit/start at     queue                          slots ja-task-ID 
-----------------------------------------------------------------------------------------------------------------
2949274 0.00000 printenv   tgardos      qw    02/04/2026 14:47:55  

The -u userID option only shows your jobs. Leave it off and you will see all the jobs currently queued.

You see it lists the

  • job ID
  • priority of the job
  • name of the job
  • user
  • job’s state in the queue – here it is qw (waiting to run).
  • submission/start time
  • queue – the queue name if the job is running

At some point qstat will no longer show any jobs in the queue. This one doesn’t run for long, so you probably won’t catch it running, but if you do, it will look like this:

$ qstat -u tgardos
job-ID  prior   name       user         state submit/start at     queue                          slots ja-task-ID 
-----------------------------------------------------------------------------------------------------------------
2949274 0.74554 printenv   tgardos      r     02/04/2026 14:49:56 academic@scc-gf1.scc.bu.edu        1   

After the job finishes, you’ll see in the directory you submitted the job from 2 files:

$ ls -l
total 1
-rw-r--r-- 1 tgardos dl4ds-ta    0 Feb  4 14:49 printenv.e2949274
-rw-r--r-- 1 tgardos dl4ds-ta 2062 Feb  4 14:49 printenv.o2949274

Notice the files are the job name with either a .e<jobID> or .o<jobID> output.

These are standard and error outputs of the job.

In this case the error output was 0 bytes, but the job output was

$ cat printenv.o294013
QUEUE=cds
SGE_O_HOST=scc1
HOSTNAME=scc-tc4.scc.bu.edu
ENVIRONMENT=BATCH
REQUEST=printenv
SGE_STDIN_PATH=/dev/null
SGE_CELL=default
NHOSTS=1
SGE_O_WORKDIR=/usr2/faculty/tgardos
...

Which is the printout of the environment variables on the node the job was executed on, which was scc-tc4.scc.bu.edu.

You’ll also see a lot environment variabels with SGE_ prefix, which are apparently set as part of the Sun Grid Engine batch queueing system.

qacct command

You can get information about completed jobs with

$ qacct -j 2949274
==============================================================
qname        engineering         
hostname     scc-pi6.scc.bu.edu  
group        mhcpep              
owner        gychuang            
project      mhcpep              
department   defaultdepartment   
jobname      sge.jcf             
jobnumber    2949274             
taskid       undefined
account      sge                 
priority     0                   
qsub_time    Tue Mar  4 00:25:36 2025
start_time   Tue Mar  4 00:27:53 2025
end_time     Tue Mar  4 00:27:54 2025
granted_pe   mpi4                
slots        4                   
failed       0    
exit_status  1                   
ru_wallclock 1            
ru_utime     0.207        
ru_stime     0.111        
ru_maxrss    19576               
ru_ixrss     0                   
ru_ismrss    0                   
ru_idrss     0                   
ru_isrss     0                   
ru_minflt    18585               
ru_majflt    0                   
ru_nswap     0                   
ru_inblock   0                   
ru_oublock   40                  
ru_msgsnd    0                   
ru_msgrcv    0                   
ru_nsignals  0                   
ru_nvcsw     1786                
ru_nivcsw    38                  
cpu          0.318        
mem          0.000             
io           0.000             
iow          0.000             
maxvmem      0.000
arid         undefined
==============================================================
qname        academic            
hostname     scc-gf1.scc.bu.edu  
group        dl4ds               
owner        tgardos             
project      dl4ds               
department   defaultdepartment   
jobname      printenv            
jobnumber    2949274             
taskid       undefined
account      sge                 
priority     0                   
qsub_time    Wed Feb  4 14:47:55 2026
start_time   Wed Feb  4 14:49:56 2026
end_time     Wed Feb  4 14:49:56 2026
granted_pe   NONE                
slots        1                   
failed       0    
exit_status  0                   
ru_wallclock 0            
ru_utime     0.008        
ru_stime     0.014        
ru_maxrss    3676                
ru_ixrss     0                   
ru_ismrss    0                   
ru_idrss     0                   
ru_isrss     0                   
ru_minflt    777                 
ru_majflt    0                   
ru_nswap     0                   
ru_inblock   8                   
ru_oublock   24                  
ru_msgsnd    0                   
ru_msgrcv    0                   
ru_nsignals  0                   
ru_nvcsw     64                  
ru_nivcsw    0                   
cpu          0.022        
mem          0.000             
io           0.000             
iow          0.000             
maxvmem      0.000
arid         undefined

We’ll come back to why ‘department’ and ‘project’ maybe impact which resources have access to.

qdel command

You can delete a job waiting in queue with qdel jobID command.

Other Interactive Tools

We’re going to be playing with some short scripts. You can do everything via the SCC Dashboard login node and text editors, but there are alternatives:

  • ssh into a login node, ssh <username>@scc1.bu.edu
  • start an interactive VS Code server
  • start an interactive desktop and open VS Code or terminal

It’s also to use a local instance of VS Code with Remote Extension Pack.

Note: This is not officially supported by SCC and has the annoying problem of having to re-connect to the remote host every time you restart VS Code.

  1. Open VS Code locally on your machine.
  2. Install the “Remote Development” extension pack by Microsoft from the extension marketplace.
  3. Now connect to remote host scc1.bu.edu, follow the prompts to connect.
  4. From the Terminal menu, open a new terminal.

Submitting a script

In general we don’t want to run a single binary command but rather usually a python script with some environment configuration first.

For that it’s best to submit a shell script that configures the environment and then runs the python script.

So let’s create a shell script

scriptv1.sh
#!/bin/bash -l

echo "Print python version"
python --version

python myscript.py
Important

To be processed correctly, the shell script must have a blank line at the end of the file.

You see that it is running a python script, that in this case can be a simple script

myscript.py
print("Hello batched world!")

We can submit and check the status.

$ qsub scriptv1.sh 
Your job 294119 ("scriptv1.sh") has been submitted

$ qstat -u tgardos
job-ID  prior   name       user         state submit/start at     queue                          slots ja-task-ID 
-----------------------------------------------------------------------------------------------------------------
 294119 0.00000 scriptv1.sh  tgardos      qw    09/21/2024 21:12:46                                    1        

Actually, in this case, I caught the queue status while it was running

$ qstat -u tgardos
job-ID  prior   name       user         state submit/start at     queue                          slots ja-task-ID 
-----------------------------------------------------------------------------------------------------------------
 294119 1.10000 scriptv1.sh  tgardos      r     09/21/2024 21:14:04 cds@scc-tc3.scc.bu.edu             1        

And cat the output

$ cat scriptv1.sh.o294119 
Print python version
Python 3.6.8
Hello batched world!
Tip

By the way, even for longer jobs, I will start the script manually just to make sure it starts ok, then kill it, instead of waiting for it to queueu and run to find out I made a simple mistake in sthe script.

Caution

This won’t work if you want to train on a GPU, but you can use the qrsh command to get a GPU node.

$ source scriptv1.sh
Print python version
Python 3.6.8
Hello batched world!

Setting up batch job environment

So one thing you’ll notice is that the python version is 3.6.8, which is not the latest version. So let’ update our script.

scriptv2.sh
#!/bin/bash -l

module load python3/3.12.4

echo "Print python version"
python --version

python myscript.py

Now when we run

$ source scriptv2.sh 
Print python version
Python 3.12.4
Hello batched world!

Job Submission Directives

We can add job submission directives to our shell script with lines beginning with #$.

scriptv3.sh
#!/bin/bash -l

#$ -P dl4ds           # Assign to project dl4ds
#$ -l h_rt=12:00:00   # Set a hard runtime limit
#$ -N hello-world     # Give the job a name other than the shell script name
#$ -j y               # merge the error and regular output into a single file

module load python3/3.12.4

echo "Print python version"
python --version

python myscript.py

Other general job submission directives are listed here

Requesting Resources

Let’s look at how to request particular resources for our job.

Here’s simply python code that checks if a GPU is available, and if so transforms a simple tensor into a CUDA tensor.

Note

CUDA is the Nvidia GPU driver and software package.

cuda-simple.py
import torch

print(f'torch cuda is available: {torch.cuda.is_available()}')
t = torch.tensor([1, 2, 3])

if torch.cuda.is_available():
    t = t.cuda()

print(t)

And we create a job submission script that loads the SCC academic ML environment and activates it.

run-cuda-simple.sh
#!/bin/bash -l

#$ -P dl4ds           # Assign to project dl4ds
#$ -j y               # merge the error and regular output into a single file

module load miniconda academic-ml/spring-2026

conda activate spring-2026-pyt

echo "Print python version"
python --version

python cuda-simple.py

# to be processed correctly there must be a blank line at the end of the file

Let’s submit two jobs:

One to run on default compute node (no GPU)

$ qsub run-cuda-simple.sh 
Your job 316551 ("run-cuda-simple.sh") has been submitted

And one job where we request 1 GPU.

$ qsub -l gpus=1 run-cuda-simple.sh 
Your job 316561 ("run-cuda-simple.sh") has been submitted

In this case, it created an output file for each job:

ls -ls
run-cuda-simple.sh.o316551
run-cuda-simple.sh.o316561

Let’s look at the one where we didn’t request a GPU.

run-cuda-simple.sh.o316551
-------------------------------------------------------------------------------
To activate the conda environment in a batch script or in a terminal run the
following command. For interactive sessions in SCC OnDemand place this command
in the "Pre-Launch Command" field.

To load the PyTorch-based environment run:

    conda activate fall-2024-pyt
    
To load the Tensorflow-based environment run:

    conda activate fall-2024-tf

To load the Jax-based environment run:

    conda activate fall-2024-jax
    
For information on using or cloning this conda environment visit:

https://www.bu.edu/tech/support/research/software-and-programming/common-languages/python/python-ml/academic-machine-learning-environment
-------------------------------------------------------------------------------

Print python version
Python 3.11.9
torch cuda is available: False
tensor([1, 2, 3])

And the one where we did.

run-cuda-simple.sh.0316561
-------------------------------------------------------------------------------
To activate the conda environment in a batch script or in a terminal run the
following command. For interactive sessions in SCC OnDemand place this command
in the "Pre-Launch Command" field.

To load the PyTorch-based environment run:

    conda activate fall-2024-pyt
    
To load the Tensorflow-based environment run:

    conda activate fall-2024-tf

To load the Jax-based environment run:

    conda activate fall-2024-jax
    
For information on using or cloning this conda environment visit:

https://www.bu.edu/tech/support/research/software-and-programming/common-languages/python/python-ml/academic-machine-learning-environment
-------------------------------------------------------------------------------

Print python version
Python 3.11.9
torch cuda is available: True
tensor([1, 2, 3], device='cuda:0')

You can see here for a more list of resources to specify, but a good example is

$ qsub -l gpus=1 -l gpu_c=7.0 -pe omp 8  script.sh

The argument -l qpu_c=7.0 is the GPU capability requested, which currently is one of [3.5, 5, 6.0, 6.1, 7.0, 7.5, 8.0, 8.6, 8.9, 9.0].

There’s a dedicated page for GPU Computing on the SCC.

You can list all installed GPUs with qgpus.

# Run Feb 4, 2026
$ qgpus
gpu_type  total  in_use  available
--------  -----  ------  ---------
A100          5      0      5
A100-80G     24     21      3
A40          68     31     35
A6000        76     24     52
H200         20     20      0
K40m         14      2     12
L40           6      2      4
L40S        118     87     30
P100         28     10     18
P100-16G     23      4     19
RTX6000       5      0      5
RTX6000ada     30     18     12
RTX8000       8      2      6
TitanV        8      0      8
TitanXp      10      0     10
V100         65     33     31
V100-32G      4      3      1

To see more details, the resource number and which queues they’re on, you can use qgpus -v.

# Run on Feb 4, 2026
$ qgpus -v
host      gpu_type  gpu_c  gpu_mem  cpu_   cpu_    gpu_   gpu_    gpu_   queue_list                    
                                    total  in_use  total  in_use  avail                                
--------  --------  -----  -------  -----  ------  -----  ------  -----  ------------------------------
scc-205   A100      8.0    40G      32     0       4      0       4      thinfilament-gpu,thinfilament-gpu-pub
scc-207   A100      8.0    40G      32     1       1      0       1      li-rbsp-gpu-pub,li-rbsp-gpu   
scc-210   A100      8.0    80G      32     32      4      4       0      neuro-autonomy,neuro-autonomy-pub
scc-212   A100      8.0    80G      32     7       4      4       0      a100                          
scc-219   A100      8.0    80G      32     12      2      1       1      joshigroup-gpu,joshigroup-gpu-pub
scc-220   A100      8.0    80G      32     16      4      4       0      labcigroup-gpu-pub,labcigroup-gpu
scc-221   A100      8.0    80G      32     0       2      0       2      chapmangroup-gpu,chapmangroup-gpu-pub
scc-305   A100      8.0    80G      48     48      4      4       0      cds-gpu-pub,cds-gpu,cds-gpu-long
scc-306   A100      8.0    80G      48     48      4      4       0      cds-gpu-pub,cds-gpu,cds-gpu-long
scc-211   A40       8.6    48G      32     10      4      4       0      a40                           
scc-213   A40       8.6    48G      32     0       2      0       2      csgpu-pub,csgpu               
scc-214   A40       8.6    48G      32     16      4      4       0      ece-pub,ece,ece-long          
scc-215   A40       8.6    48G      32     0       4      0       4      ece-pub,ece,ece-long          
scc-216   A40       8.6    48G      32     0       4      0       4      ece-pub,ece,ece-long          
scc-217   A40       8.6    48G      32     4       2      1       1      csgpu-pub,csgpu               
scc-218   A40       8.6    48G      32     16      2      2       0      csgpu-pub,csgpu               
scc-301   A40       8.6    48G      32     0       6      0       6      neuro-autonomy,neuro-autonomy-pub
scc-302   A40       8.6    48G      32     32      6      4       0      neuro-autonomy,neuro-autonomy-pub
scc-303   A40       8.6    48G      32     0       10     0       10     iris-gpu,iris-gpu-pub         
scc-f03   A40       8.6    48G      32     0       6      0       6      neuro-autonomy,neuro-autonomy-pub
scc-f04   A40       8.6    48G      32     22      10     10      0      ivcbuyin-long,ivcbuyin,ivcbuyin-pub
scc-f05   A40       8.6    48G      32     10      8      6       2      ivcbuyin,ivcbuyin-pub         
scc-307   A6000     8.6    48G      32     0       4      0       4      batcomputer,batcomputer-pub   
scc-603   A6000     8.6    48G      32     4       5      1       4      iris-gpu,iris-gpu-pub         
scc-604   A6000     8.6    48G      32     0       8      0       8      iris-gpu,iris-gpu-pub         
scc-605   A6000     8.6    48G      32     0       8      0       8      iris-gpu,iris-gpu-pub         
scc-606   A6000     8.6    48G      32     0       8      0       8      iris-gpu,iris-gpu-pub         
scc-607   A6000     8.6    48G      32     0       6      0       6      iris-gpu,iris-gpu-pub         
scc-608   A6000     8.6    48G      32     0       8      0       8      iris-gpu,iris-gpu-pub         
scc-e01   A6000     8.6    48G      32     20      9      5       4      ivcbuyin,ivcbuyin-pub         
scc-e02   A6000     8.6    48G      32     24      10     10      0      ivcbuyin,ivcbuyin-pub         
scc-e03   A6000     8.6    48G      32     12      10     8       2      ivcbuyin,ivcbuyin-pub         
scc-a03   H200      9.0    144G     32     32      4      4       0      h200                          
scc-a04   H200      9.0    144G     32     17      4      4       0      h200                          
scc-a05   H200      9.0    144G     32     28      4      4       0      ece-pub,ece,ece-long          
scc-a06   H200      9.0    144G     32     32      4      4       0      ece-pub,ece,ece-long          
scc-a15   H200      9.0    144G     32     32      2      2       0      cds-gpu-pub,cds-gpu,cds-gpu-long
scc-a16   H200      9.0    144G     32     32      2      2       0      cds-gpu-pub,cds-gpu,cds-gpu-long
scc-c01   K40m      3.5    12G      20     3       2      2       0      katia,k40                     
scc-c04   K40m      3.5    12G      20     0       4      0       4      kulisgpu,kulisgpu-pub         
scc-c05   K40m      3.5    12G      20     0       4      0       4      kulisgpu,kulisgpu-pub         
scc-sc1   K40m      3.5    12G      16     0       2      0       2      tcn-pub,tcn                   
scc-sc2   K40m      3.5    12G      16     0       2      0       2      tcn-pub,tcn                   
scc-304   L40       8.9    48G      32     8       6      2       4      ivcbuyin,ivcbuyin-pub         
scc-501   L40S      8.9    48G      32     17      4      4       0      l40s                          
scc-502   L40S      8.9    48G      32     32      4      3       0      l40s                          
scc-503   L40S      8.9    48G      32     10      4      4       0      l40s                          
scc-504   L40S      8.9    48G      32     15      4      4       0      l40s                          
scc-505   L40S      8.9    48G      32     28      4      4       0      l40s                          
scc-506   L40S      8.9    48G      32     0       4      0       4      l40s                          
scc-507   L40S      8.9    48G      32     20      2      2       0      czcb-buyin,czcb-buyin-pub     
scc-508   L40S      8.9    48G      32     0       2      0       2      csgpu-pub,csgpu               
scc-509   L40S      8.9    48G      32     4       2      1       1      csgpu-pub,csgpu               
scc-510   L40S      8.9    48G      32     17      4      4       0      l40s                          
scc-511   L40S      8.9    48G      32     21      4      4       0      l40s                          
scc-512   L40S      8.9    48G      32     21      4      4       0      l40s                          
scc-513   L40S      8.9    48G      32     28      4      4       0      l40s                          
scc-601   L40S      8.9    48G      32     24      8      6       2      cuigpu,cuigpu-pub             
scc-a01   L40S      8.9    48G      32     28      8      7       1      cuigpu,cuigpu-pub             
scc-a02   L40S      8.9    48G      32     20      8      5       3      cuigpu,cuigpu-pub             
scc-j01   L40S      8.9    48G      32     8       4      1       3      ece-pub,ece,ece-long          
scc-j02   L40S      8.9    48G      32     8       4      1       3      ece-pub,ece,ece-long          
scc-j03   L40S      8.9    48G      32     12      4      2       2      ece-pub,ece,ece-long          
scc-j04   L40S      8.9    48G      32     16      4      1       3      ece-pub,ece,ece-long          
scc-j05   L40S      8.9    48G      32     8       4      2       2      ece-pub,ece,ece-long          
scc-j06   L40S      8.9    48G      32     24      4      4       0      ece-pub,ece,ece-long          
scc-j07   L40S      8.9    48G      32     4       4      4       0      ece-pub,ece,ece-long          
scc-j08   L40S      8.9    48G      32     20      4      3       1      ece-pub,ece,ece-long          
scc-j09   L40S      8.9    48G      32     0       2      0       2      csgpu-pub,csgpu               
scc-j10   L40S      8.9    48G      32     4       2      1       1      csgpu-pub,csgpu               
scc-j11   L40S      8.9    48G      32     17      4      4       0      cds-gpu-pub,cds-gpu,cds-gpu-long
scc-j12   L40S      8.9    48G      32     16      4      4       0      cds-gpu-pub,cds-gpu,cds-gpu-long
scc-j13   L40S      8.9    48G      32     16      4      4       0      cds-gpu-pub,cds-gpu,cds-gpu-long
scc-c08   P100      6.0    12G      28     8       2      1       1      p100                          
scc-c09   P100      6.0    12G      28     17      2      2       0      p100                          
scc-c10   P100      6.0    12G      28     12      2      2       0      p100                          
scc-c11   P100      6.0    12G      28     24      2      2       0      p100                          
scc-c12   P100      6.0    12G      28     4       4      1       3      csgpu-pub,csgpu               
scc-c13   P100      6.0    12G      28     0       4      0       4      ece-pub,ece,ece-long          
scc-c14   P100      6.0    12G      28     0       4      0       4      ece-pub,ece,ece-long          
scc-x01   P100      6.0    12G      28     16      2      2       0      onrcc-gpu,onrcc-gpu-pub       
scc-x02   P100      6.0    12G      28     0       2      0       2      onrcc-gpu,onrcc-gpu-pub       
scc-x03   P100      6.0    12G      28     0       2      0       2      onrcc-gpu,onrcc-gpu-pub       
scc-x04   P100      6.0    12G      28     0       2      0       2      onrcc-gpu,onrcc-gpu-pub       
scc-k01   P100      6.0    16G      28     24      4      3       1      ece-pub,ece,ece-long          
scc-k02   P100      6.0    16G      28     8       4      1       3      ece-pub,ece,ece-long          
scc-k03   P100      6.0    16G      28     0       4      0       4      cuigpu,cuigpu-pub             
scc-k04   P100      6.0    16G      28     0       4      0       4      cuigpu,cuigpu-pub             
scc-k05   P100      6.0    16G      28     0       4      0       4      cuigpu,cuigpu-pub             
scc-k06   P100      6.0    16G      28     0       1      0       1      csdata,csdata-pub             
scc-k07   P100      6.0    16G      28     12      2      0       2      bil-koo-gpu,bil-koo-gpu-pub   
scc-f02   RTX6000   7.5    24G      32     0       5      0       5      ivcbuyin,ivcbuyin-pub         
scc-308   RTX6000ada  8.9    48G      32     24      4      4       0      batcomputer,batcomputer-pub   
scc-309   RTX6000ada  8.9    48G      64     25      10     7       3      ivcbuyin,ivcbuyin-pub         
scc-602   RTX6000ada  8.9    48G      32     0       8      0       8      cuigpu,cuigpu-pub             
scc-609   RTX6000ada  8.9    48G      64     20      8      7       1      ivcbuyin,ivcbuyin-pub         
scc-e04   RTX8000   7.5    48G      32     8       8      2       6      ivcbuyin,ivcbuyin-pub         
scc-f01   TitanV    7.0    12G      24     0       8      0       8      ivcbuyin-int                  
scc-e05   TitanXp   6.1    12G      28     0       10     0       10     ivcbuyin,ivcbuyin-pub         
scc-201   V100      7.0    16G      32     32      4      4       0      academic-gpu-pub,academic-gpu 
scc-202   V100      7.0    16G      32     4       4      1       3      academic-gpu-pub,academic-gpu 
scc-203   V100      7.0    16G      32     0       4      0       4      academic-gpu-pub,academic-gpu 
scc-204   V100      7.0    16G      32     8       4      2       2      academic-gpu-pub,academic-gpu 
scc-k08   V100      7.0    16G      28     4       2      1       1      thinfilament-gpu,thinfilament-gpu-pub
scc-k09   V100      7.0    16G      28     5       2      2       0      casaq-gpu,casaq-gpu-pub       
scc-k10   V100      7.0    16G      28     28      1      0       0      bil-koo-gpu,bil-koo-gpu-pub   
scc-k11   V100      7.0    16G      28     4       2      1       1      csgpu-pub,csgpu               
scc-q23   V100      7.0    16G      32     8       1      1       0      korolevgroup-gpu-pub,korolevgroup-gpu
scc-q24   V100      7.0    16G      32     8       1      1       0      labcigroup-gpu-pub,labcigroup-gpu
scc-q25   V100      7.0    16G      32     0       2      0       2      csgpu-pub,csgpu               
scc-q26   V100      7.0    16G      32     0       2      0       2      csgpu-pub,csgpu               
scc-q27   V100      7.0    16G      32     16      2      1       1      csgpu-pub,csgpu               
scc-q28   V100      7.0    16G      32     0       2      0       2      csgpu-pub,csgpu               
scc-q30   V100      7.0    16G      28     16      4      1       3      jchengroup,jchengroup-pub     
scc-q31   V100      7.0    16G      32     4       4      4       0      cds-gpu-pub,cds-gpu,cds-gpu-long
scc-q32   V100      7.0    16G      32     4       4      4       0      cds-gpu-pub,cds-gpu,cds-gpu-long
scc-q33   V100      7.0    16G      32     0       4      0       4      ece-pub,ece,ece-long          
scc-q34   V100      7.0    16G      32     0       4      0       4      ece-pub,ece,ece-long          
scc-q35   V100      7.0    16G      32     20      4      4       0      biophys-gpu-pub,biophys-gpu   
scc-q36   V100      7.0    16G      32     12      4      2       2      aclabgroup,aclabgroup-pub     
scc-x05   V100      7.0    16G      28     20      2      2       0      v100                          
scc-x06   V100      7.0    16G      28     2       2      2       0      v100                          
scc-208   V100      7.0    32G      32     8       2      2       0      thinfilament-gpu,thinfilament-gpu-pub
scc-209   V100      7.0    32G      32     0       1      0       1      cuigpu,cuigpu-pub             
scc-q29   V100      7.0    32G      32     4       1      1       0      korolevgroup-gpu-pub,korolevgroup-gpu

And the GPUs on CDS queues:

# Run on Feb 26, 2026
$ qgpus -v | grep cds
scc-305   A100      8.0    80G      48     48      4      4       0      cds-gpu-pub,cds-gpu,cds-gpu-long
scc-306   A100      8.0    80G      48     48      4      4       0      cds-gpu-pub,cds-gpu,cds-gpu-long
scc-a15   H200      9.0    144G     32     32      2      2       0      cds-gpu-pub,cds-gpu,cds-gpu-long
scc-a16   H200      9.0    144G     32     32      2      2       0      cds-gpu-pub,cds-gpu,cds-gpu-long
scc-j11   L40S      8.9    48G      32     17      4      4       0      cds-gpu-pub,cds-gpu,cds-gpu-long
scc-j12   L40S      8.9    48G      32     16      4      4       0      cds-gpu-pub,cds-gpu,cds-gpu-long
scc-j13   L40S      8.9    48G      32     16      4      4       0      cds-gpu-pub,cds-gpu,cds-gpu-long
scc-q31   V100      7.0    16G      32     4       4      4       0      cds-gpu-pub,cds-gpu,cds-gpu-long
scc-q32   V100      7.0    16G      32     4       4      4       0      cds-gpu-pub,cds-gpu,cds-gpu-longer

Exploring Queues

You can explore the queues a bit more with the qselect command.

We can count the total number of queues:

$ qselect | wc -l
1776

The number of queues with at least one GPU.

$ qselect -l gpus=1 | wc -l
214

We can search for queues with ‘cds’ in the name:

$ qselect -q *cds*
cds-m1024-pub@scc-v08.scc.bu.edu
cds-pub@scc-tb3.scc.bu.edu
cds-pub@scc-tc4.scc.bu.edu
cds-pub@scc-ga4.scc.bu.edu
cds-pub@scc-tb2.scc.bu.edu
cds-pub@scc-ga3.scc.bu.edu
cds-pub@scc-tc1.scc.bu.edu
cds-pub@scc-tc3.scc.bu.edu
cds-pub@scc-tc2.scc.bu.edu
cds-gpu-pub@scc-j11.scc.bu.edu
cds-gpu-pub@scc-305.scc.bu.edu
cds-gpu-pub@scc-306.scc.bu.edu
cds-gpu-pub@scc-j13.scc.bu.edu
cds-gpu-pub@scc-q32.scc.bu.edu
cds-gpu-pub@scc-j12.scc.bu.edu
cds-gpu-pub@scc-q31.scc.bu.edu
cds@scc-tb3.scc.bu.edu
cds@scc-tc4.scc.bu.edu
cds@scc-ga4.scc.bu.edu
cds@scc-tb2.scc.bu.edu
cds@scc-ga3.scc.bu.edu
cds@scc-tc1.scc.bu.edu
cds@scc-tc3.scc.bu.edu
cds@scc-tc2.scc.bu.edu
cds-gpu@scc-j11.scc.bu.edu
cds-gpu@scc-305.scc.bu.edu
cds-gpu@scc-306.scc.bu.edu
cds-gpu@scc-j13.scc.bu.edu
cds-gpu@scc-q32.scc.bu.edu
cds-gpu@scc-j12.scc.bu.edu
cds-gpu@scc-q31.scc.bu.edu
cds-m1024@scc-v08.scc.bu.edu

And the count:

$ qselect -q *cds* | wc -l
32

Of those which have at least 1 GPU and the count:

$ qselect -q *cds* -l gpus=1
cds-gpu-pub@scc-j11.scc.bu.edu
cds-gpu-pub@scc-305.scc.bu.edu
cds-gpu-pub@scc-306.scc.bu.edu
cds-gpu-pub@scc-j13.scc.bu.edu
cds-gpu-pub@scc-q32.scc.bu.edu
cds-gpu-pub@scc-j12.scc.bu.edu
cds-gpu-pub@scc-q31.scc.bu.edu
cds-gpu@scc-j11.scc.bu.edu
cds-gpu@scc-305.scc.bu.edu
cds-gpu@scc-306.scc.bu.edu
cds-gpu@scc-j13.scc.bu.edu
cds-gpu@scc-q32.scc.bu.edu
cds-gpu@scc-j12.scc.bu.edu
cds-gpu@scc-q31.scc.bu.edu

$ qselect -q *cds* -l gpus=1 | wc -l
14

Example: CIFAR10 Training on CPU and GPU

Let’s put what we learned to use and train a CIFAR10 classifier with and without GPUs.

We’ll use the CIFAR10 classifer model training code from python environment notes but with some instrumentation for timing and GPU support.

It is important to note that you may be assigned 1 GPU on a multi-GPU node. You shouldn’t manually assign one of the GPUs.

Per this note you can check which GPU you are assigned with

import os
print(os.getenv("CUDA_VISIBLE_DEVICES"))

We’ll modify our training code to check if CUDA is available and use it if so:

cifar-train.py
import torch
import torch.optim as optim
import torch.nn as nn
import torch.nn.functional as F
import torchvision
import torchvision.transforms as transforms
import time

# Record the start time
start_time = time.time()

# Check if CUDA is available
device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
print(f'Using {device} device')

# Define transformations for the dataset
transform = transforms.Compose(
    [transforms.ToTensor(),
     transforms.Normalize((0.5, 0.5, 0.5), (0.5, 0.5, 0.5))])

# Download and load the CIFAR-10 dataset
trainset = torchvision.datasets.CIFAR10(root='./data', train=True, download=True, transform=transform)
trainloader = torch.utils.data.DataLoader(trainset, batch_size=32, shuffle=True)

testset = torchvision.datasets.CIFAR10(root='./data', train=False, download=True, transform=transform)
testloader = torch.utils.data.DataLoader(testset, batch_size=32, shuffle=False)

# Classes
classes = ('plane', 'car', 'bird', 'cat', 'deer', 'dog', 'frog', 'horse', 'ship', 'truck')

# Define the CNN model
class SmallCNN(nn.Module):
    def __init__(self):
        super(SmallCNN, self).__init__()
        self.conv1 = nn.Conv2d(3, 16, 3, padding=1)
        self.conv2 = nn.Conv2d(16, 32, 3, padding=1)
        self.pool = nn.MaxPool2d(2, 2)
        self.fc1 = nn.Linear(32 * 8 * 8, 128)
        self.fc2 = nn.Linear(128, 10)

    def forward(self, x):
        x = self.pool(F.relu(self.conv1(x)))
        x = self.pool(F.relu(self.conv2(x)))
        x = x.view(-1, 32 * 8 * 8)
        x = F.relu(self.fc1(x))
        x = self.fc2(x)
        return x

# Initialize the model, loss function, and optimizer
model = SmallCNN().to(device)
criterion = nn.CrossEntropyLoss()
optimizer = optim.SGD(model.parameters(), lr=0.001, momentum=0.9)

# Training the model
def train_model(model, trainloader, criterion, optimizer, epochs=5):
    for epoch in range(epochs):  # Loop over the dataset multiple times
        running_loss = 0.0
        for i, data in enumerate(trainloader, 0):
            # Get the inputs; data is a list of [inputs, labels]
            inputs, labels = data[0].to(device), data[1].to(device)

            # Zero the parameter gradients
            optimizer.zero_grad()

            # Forward pass
            outputs = model(inputs)
            loss = criterion(outputs, labels)

            # Backward pass and optimize
            loss.backward()
            optimizer.step()

            # Print statistics
            running_loss += loss.item()
            if i % 100 == 99:    # Print every 100 mini-batches
                print(f'[Epoch {epoch + 1}, Batch {i + 1}] loss: {running_loss / 100:.3f}')
                running_loss = 0.0

    print('Finished Training')

    # Using the TorchScript method for model saving
    # Important! Do not change the following 2 lines of code except for the model name
    scripted_model = torch.jit.script(model)
    torch.jit.save(scripted_model, 'cifar10-model.pt')

    print('Model saved as cifar10-model.pt')

# Call the training function
train_model(model, trainloader, criterion, optimizer)

# Evaluation function to test the accuracy
def evaluate_model(model, testloader):
    correct = 0
    total = 0
    with torch.no_grad():
        for data in testloader:
            images, labels = data[0].to(device), data[1].to(device)
            outputs = model(images)
            _, predicted = torch.max(outputs.data, 1)
            total += labels.size(0)
            correct += (predicted == labels).sum().item()

    accuracy = 100 * correct / total
    print(f'Accuracy of the network on the 10,000 test images: {accuracy:.2f}%')
    return accuracy

# Call the evaluation function
evaluate_model(model, testloader)

# Record the end time
end_time = time.time()

# Calculate the elapsed time
elapsed_time = end_time - start_time
minutes, seconds = divmod(elapsed_time, 60)

# Print the elapsed time in minutes and seconds
print(f"Elapsed time: {int(minutes)} minutes and {seconds:.2f} seconds")

with the script

run-cifar-train.sh
#!/bin/bash -l

#$ -P dl4ds           # Assign to project dl4ds
#$ -j y               # merge the error and regular output into a single file

module load miniconda academic-ml/fall-2024

conda activate fall-2024-pyt

echo "Print python version"
python --version

python cifar-train.py

# to be processed correctly there must be a blank line at the end of the file

And submit both with and without GPU

$ qsub run-cifar-train.sh 
Your job 317438 ("run-cifar-train.sh") has been submitted

$ qsub -l gpus=1 run-cifar-train.sh 
Your job 317468 ("run-cifar-train.sh") has been submitted

And let’s compare the outputs:

run-cifar-train.sh.o317438 (CPU)
Print python version
Python 3.11.9
Using cpu device
Files already downloaded and verified
Files already downloaded and verified
[Epoch 1, Batch 100] loss: 2.299
[Epoch 1, Batch 200] loss: 2.287
...
[Epoch 5, Batch 1400] loss: 1.113
[Epoch 5, Batch 1500] loss: 1.092

Finished Training
Model saved as cifar10-model.pt

Accuracy: 60.38%

Elapsed time: 2 minutes and 50.11 seconds
run-cifar-train.sh.o317468 (GPU)
Print python version
Python 3.11.9
Using cuda device
Files already downloaded and verified
Files already downloaded and verified
[Epoch 1, Batch 100] loss: 2.298
[Epoch 1, Batch 200] loss: 2.278
...
[Epoch 5, Batch 1400] loss: 1.116
[Epoch 5, Batch 1500] loss: 1.129

Finished Training
Model saved as cifar10-model.pt

Accuracy: 60.80%

Elapsed time: 0 minutes and 54.14 seconds

References

  • https://www.bu.edu/tech/support/research/system-usage/running-jobs/submitting-jobs/
  • https://www.bu.edu/tech/support/research/system-usage/running-jobs/tracking-jobs/
  • https://www.bu.edu/tech/support/research/software-and-programming/gpu-computing/
  • https://www.bu.edu/tech/support/research/system-usage/running-jobs/batch-script-examples/
  • https://www.bu.edu/tech/support/research/system-usage/running-jobs/process-reaper/
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