Supercomputing

Overview

Part of the Graham supercomputer.

What isn’t a supercomputer

A super fast computer that just runs your program faster.

What is a supercomputer

Nibi (latest SHARCNET supercomputer)

  • 752 computers (nodes)

  • 143,808 cores

  • 657 petabytes (PB) of RAM (mostly 4 gigabyte (GB)/core)

  • 25 petabytes (PB) of SSD flash

  • 312 NVIDIA GPUs (H100 SXM)

  • 24 AMD GPUs (CDNA 3)

  • 400 Gbit/s Ethernet between NVIDIA GPU nodes

  • 200 Gbit/s Ethernet between CPU and AMD GPU nodes

Computer (node) from the Graham supercomputer.

How do you use a supercomputer

serial

(easy) many computers means you can run many programs indepedently at the same to solve many independent problems

parallel

(hard) many computers can (sometimes) be programmed to all collaborate and solve a single problem together

cloud

virtual computer on the internet (like Amazon’s Elastic Compute Cloud, Microsoft’s Azure cloud, or Google’s Compute Engine)

Canada

The players

National

  • Digital Research Alliannce of Canada

Regional

  • Compute Ontario, Calcul Québec, ACENET, BC DRI Group, and Prairies DRI

Ontario

  • Center for Advanced Computing (CAC), HPC4Health, SciNet, and SHARCNET

Getting an accounts

Cost

  • no cost

Who

  • faculty or those sponsored by faculty that have an account

How

What software is available

Operating system

  • Linux (CentOS 7/Rocky 8/Alma 9)

Programming languages

  • C/C++, Fortran, MATLAB/Octave, Python, R, Julia, etc.

Parallel development support

  • pthreads, MPI, OpenMP, CUDA, OpenACC, OpenCL

Other

  • common open source and commerical packages (e.g., OpenFOAM, Fluent, and STAR-CCM+)

How to use

  • resources are scheduled to avoid collisions and ensure fair access

  • access from anywhere on the internet using secure shell (SSH) to enter commands and a secure file transfer (SFTP) to transfer files

  • tell the supercomputer what progam (command) you want it to run and then do something else till it does it

Typical workflow

  1. transfer your data and/or programs to the supercomputer using SFTP

  2. login (bring up a window in which you can enter commands) to the supercomputer using SSH

  3. enter commands to tell the scheduler what you want it to run when the required resources are avaialable

  4. do something else until you get notification that your commands have completed running

  5. transfer the resulting data from the supercomputer to your computer