I heard about Ramdisks some years ago and even set up one for testing on mymachine. I didn't test it thoroughly so I couldn't really judge the performance improvements (in comparison to plain a SSD).
Ramdisks are in short parts of your working memory, which are allocated to a logical(software) disk. Therefore you can access them as an additional drive, put files and programs, as well as run simulations on them.
Programs cache in RAM anyway, but a lot of programs write to files, where they store their mesh data, intermediate results etc. Depending on the internals of the program, improvements could be possible. In my case the use would be for Finite Element calculations. The tool I use was created (and is mostly maintained) as scientific project, so many optimizations could be missing. I'm aware of possible data loss, it is acceptable, though it has to be accounted for.
Is there any advantage to be gained by using ramdisks? Has anyone tried using ramdisks for their calculations, was there any worthwhile (work/reward) improvement? Are there cases where it makes sense to use them?