Pagefile location: SSD, M.2, or Optane?

[Quartz]

Imagine that you have an application which uses all your RAM and then some. As such it uses the pagefile. Where is the best location for your pagefile? SSD, M.2, or Optane? Does PCIe v4 make a difference? Has anyone done tests?

 

[Quartz]

Investing in physical RAM is a good idea

Yet is not always possible. Threadripper CPUs are currently limited to 256 GB, for instance.