Ansys: Difference between revisions

As of December 2022, each researcher can run 4 jobs using a total of 252 anshpc (plus 4 anshpc per job).  Thus any of the following uniform job size combinations are possible: one 256 core job, two 130 core jobs, three 88 core jobs, or four 67 core jobs according to ( (252 + 4*num_jobs) / num_jobs ).  Since the best parallel performance is usually achieved by using all cores on packed compute nodes (aka full nodes), one can determine the number of full nodes by dividing the total anshpc cores with the compute node size.  For example, consider  Graham which has many 32-core (Broadwell) and some 44-core (Cascade) compute nodes, the maximum number of nodes that could be requested when running various size jobs on 32-core nodes would be: 256/32=8, 130/32=~4, 88/32=~2 or 67/32=~2 to run 1, 2, 3 or 4 simultaneous jobs respectively. To express this in equation form, for a given compute node size on any cluster, the number of compute nodes can be calculated by ( 252 + (4*num_jobs) ) / (num_jobs*cores_per_node) ) then round down and finally determine the total cores to request by multiplying the even number of nodes by the number of cores_per_node.

The SHARCNET Ansys license is made available on a first come first serve basis.  Should an unusually large number of Ansys jobs be submitted on a given day some jobs could fail on startup should insufficient licenses be available.  These events however have become very rare given the recent increase in anshpc licenses. If your research requires more licenses than SHARCNET can provide, a dedicated researcher license may be purchased (and hosted) on an Ansys license server at your local institution.

 

If more cores are needed (beyond that which the SHARCNET license can provide per user) a research group can purchase a license directly from [https://www.simutechgroup.com SimuTech] to host on their own institutional license server.  Note however that an extra 20% country-wide uplift fee must be payed if the cluster(s) to be used are not co-located at the institution.  Waterloo researchers who only use Graham will therefore be exempt since Graham is physically located at their campus.

Researchers can also purchase their own ansys license subscription from [https://www.cmc.ca/subscriptions/ CMC] and use their remote license servers.  Doing so will have several benefits 1) a local institutional license server is not needed 2) a physical license does not need to be obtained upon each renewal 3) the license can be used [https://www.cmc.ca/ansys-campus-solutions-cmc-00200-04847/ almost] anywhere including at home, institutions, or any alliance cluster across Canada and 4) download and installation instructions for the windows version of ansys are provided so researchers can run spaceclaim on their own computer (not possible on the Alliance since all systems are linux based).  There is however one potentially serious limitation to be aware of, according to the CMC [https://www.cmc.ca/qsg-ansys-cadpass-r20/ Ansys Quick Start Guides] one Ansys user may run a simulation on a maximum number of 64 cores.