Much like a cat can stretch out and somehow occupy an entire queen-sized bed, Linux will happily cache your file system as long as there is available memory.
Note for the "unused RAM is wasted RAM" people, in the description of earlyoom:
Why is "available" memory checked as opposed to "free" memory? On a healthy Linux system, "free" memory is supposed to be close to zero, because Linux uses all available physical memory to cache disk access. These caches can be dropped any time the memory is needed for something else.
I use both Fedora (daily driver) and Windows 11 Pro (gaming), and Windows doesn't use much more RAM honestly. Fedora uses currently 10.5 GB of RAM with Firefox, Spotify, Plex, and Telegram running (looks like a couple of YouTube tabs in Firefox are having a party here with 1 GB of used RAM for three tabs...), and Windows is typically only 1-2 GB above this with the same type of usage. I have never maxed out my 32 GB of RAM on either OSs.
You have a lot of ram, linux will try to use most of it, it's a normal thing. There's a huge difference from using a large amount of ram when available to NEEDING that amount to run.Try installing both OSes on a machine with 4gb, and see the difference between them. One will be usable, while the other will have a poor performance. You can even push it harder with a 1gb machine. Linux will provide a system with basic functionality, while windows will be unusable.
I have the same setup - Fedora daily driver and Windows 11 Pro. I recently switched from Windows daily driver and it's crazy how much better my laptop runs with Fedora. Processor temp and RAM usage are both less than half of what they were on Windows.
I actually do this with NixOS impermanence lol. The things I need are symlinked from a different partition and the stuff I don't need automatically gets wiped clean.
The cat is the Rimworld mod with a hefty memory leak yesterday. 32 GB was full in seconds. But it gave me enough time to find the culprit and kill Rimworld without trashing my session every time.
I genuinely don't know how people are having their web browser use so much ram. How many tabs do you have open? Even at work where I run a commercial loan origination system and our core customer system in a web browser, at most I'll have 15-20 tabs open. I don't know how people are having dozens and dozens of tabs open that they're using 64 gb of RAM.
In my case, along with using my laptop as a regular PC, I also use this as my work computer. I contract for multiple companies and each window has tabs for each web software for every company, organized by consolidated tabs. So Google analytics, Crazyegg, tableau, and docs, calendar, etc. I also do web testing and each tab has tests.
I find that Edge does a better job at memory management so it's now my primary and I test on Chrome.
"Free" memory is actually usually used for cache. So instead of waiting to get data from the disk, the system can just read it directly from RAM after the first access. The more RAM you have, the more free space you'll have to use for cache. My machine often has over 20GB of RAM used as cache. You can see this with free -m. IIRC both Gnome and KDE's system managers also show that now.
