Service Units

One service unit (SU) is approximately equal to 1 core hour of computing. The charge is calculated based on factors that the slurm workload manager calls 'Trackable RESources' or TRES. The important TRES values for calculating CRC SUs are:

  • Number of cores requested
  • RAM requested
  • On the GPU cluster, number of cards requested.

Each of these has a TRES Billing Weight assigned to it in the cluster configuration files. These weights along with the amount of resources your job is allocated are used to construct a total cost in SUs.  Here is a table listing the weights for each cluster and partition:

Cluster Partition CPU/GPU Weight Memory Weight
SMP      
  smp 0.8 0.102
  high-mem 1.0 0.0477
  legacy 0.33 0.085
MPI      
  opa 1 0.445
  opa-high-mem 1 0.149
  ib 1 0.159
  mpi 1 0.93
GPU      
  gtx1080 1 0
  titanx 1 0
  k40 3 0
  v100 5 0
  power9 5 0
  a100 8 0
HTC      
  htc 1 0.128

    For a concise view of the TRES used by a job, you can use the sacct command:

    [nlc60@login0b ~] : sacct -X -M smp -j 6169876 --format=User,JobID,Jobname,AllocTRES%30,Elapsed
         User        JobID    JobName                      AllocTRES    Elapsed
    --------- ------------ ---------- ------------------------------ ----------
        nlc60 6169876      hello_wor+         cpu=1,mem=4018M,node=1   00:00:01
    

    Some examples calculations: