[OnlyMortal]

Having been asked to port CERN C++ code to the Mac, I can tell you that some scientists don’t know or even care about performance.

For those folks, getting the output they need is much more important than the CPU cycles - as it should be.

As a C++ programmer, I posed the question as to why they don’t hire coders to do this for them. The answer was cost which rather surprised me given the cost of the LHC.

[amadio]

This is not true. Maybe a PhD student doesn't care much (or doesn't know), but we care deeply about software performance at CERN. I've worked myself on optimizations in detector simulation and data analysis software (Geant4 and ROOT) for a few years. Later in this decade, when HL-LHC comes online, the only way to be able to cope with the 10x increase in data rate from experiments and a matching increase in simulation requirements will be to optimize as much as we can the software we have, because we will not have the money to just buy 10x the hardware we have now.

[OnlyMortal]

It came via Bristol University. Make of that what you will.

[amadio]

Just to complement what I said above, here's a link to a presentation I made a couple of years ago about performance optimizations in simulation: https://indico.cern.ch/event/1052654/contributions/4521602/

We also have meetings dedicated to performance, some of which are not public, but this series from ROOT is: https://indico.cern.ch/category/14122/ If you search above, you will see many discussions about performance. The CI for ROOT also has a set of benchmarks to catch regressions, and Geant4 has two systems to track performance, a CI job checking every merge request, which I've set up myself (not publicly accessible), and a more complex system to track performance run by FNAL: https://g4cpt.fnal.gov/

These are just some examples from the projects I've worked on. There are also efforts to port stuff to GPUs and HPCs, and many other projects like event generators that are also undergoing performance work for HL-LHC. If you Google you can probably find a lot more stuff than what I already mentioned. Cheers,