Compute Canada's Graham cluster is a new an HPC system at the University of Waterloo. While the Niagara system is a more direct replacement of SciNet, we're moving to Graham instead as it has better support for our workloads, replacing our old use of the SciNet system. In general, the HPF grid is slightly more convenient for typical uses, but Graham has some advantages (in particular, it's easier to get collaborators a Graham account).
If your PI has a Compute Canada RAC allocation above the default (currently no MICe PIs do), you'll need to tell the scheduler which allocation to use to run your jobs or you'll get an error from sbatch ("You are associated with multiple _cpu allocations..."). One way to do so is via environment variables:
From https://ccdb.computecanada.ca/ (My Account -> Account Details) one sees:
|iww-954-aa||def-jlerch||Default Resource Allocation Project||2 allocations|
|iww-954-ad||rrg-jlerch-ac||Using Medical Imaging to Understand the Relationship Between Genetics, Development and Disease||5 allocations, RAC 2015|
The idea here is that jobs are by default submitted under the allocation of group def-jlerch.
See here; please edit if you find a paper for Graham (as there is was for SciNet).