I discovered this about 20yrs ago and there’s been a lot of drugs & drink since then.

I do distinctly remember I could open my shit-hot 256Mb RAM desktop with Windows XP taskmanager and it shows a whopping 128Mb free RAM. 😎

Then I’d boot into my ‘733T H4X0r’ Suse Linux 7.3 and top would show 5Mb free RAM. 😱

This caused much upset until I found out the two OS’s have (had?) fundamentally different memory utilisation philosophies.

May not be the case anymore but it was late 90s/early 00s.