[Beowulf] Heterogeneity in a tiny (two-system cluster)?

[Tad Slawecki]

Hello, list -

We are at a point where we'd like to explore a tiny cluster of two systems to speed up execution of the FVCOM circulation model. We already have a two-year-old  system with two 14-core CPUs (Xeon E-2680), and I have budget to purchase another system at this point, which we plan to directly connect via Infiniband. Should I buy an exact match, or go with the most my budget can handle (for example 2xXeon Gold 1630, 16-cores) under the assumption that the two-system cluster will operate at about the same speed *and* I can reap the benefits of the added performance when running smaller simulations independently?

Our list owner already provided some thoughts:

> I've always preferred homgenous clusters, but what you say is,
> I think, quite plausible.  The issue you will have though is
> ensuring that the application is built for the earliest of the
> architectures so you don't end up using instructions for a newer
> CPU on the older one (which would result in illegal instruction
> crashes).
>
> But there may be other gotchas that others think of!

Thank you ...

Tad