I’m a PhD student and several of my classmates use computing clusters in their work. These types of computers typically have a lot of CPUs, GPUs, or both. The types of simulations they do are essentially putting a bunch of atoms or molecules in a box and seeing what happens in order to get information which is impossible to obtain experimentally. Simulating beyond a few nanoseconds in a reasonable amount of time is extremely difficult and requires a lot of compute time. However, there are plenty of other uses.

The clusters we have would have dozens of these CPUs or GPUs and users would submit jobs to it which would run simultaneously. AMD CPUs have better performance than Intel and Nvidia GPUs have Cuda, which is incorporated into a lot of the software people use for these.

I’ve personally never used anything more than a desktop, though I might apply for some time soon because I’ve got some datasets where certain fits take up to two days each. I don’t want to sit around for a month waiting for these to finish