Is it Best to Use 1 Hard Drive or 2 Hard Drives with PP and AE?

[Blast1]

[Vincent Becquiot] “someone told me once that it is better to actually install the Premiere files, which usually go in “Program files” on another drive than the operating system’s”

There is no advantage that I’ve seen, system efficiency is best served by Processor speed, enough memory, data source drive speed, and how the data souces are arranged.