Even setting it to 256GB is a much better idea than just turning off GC. I recommend to maybe halve that to leave just enough RAM for Chrome.
I've been running emacs since I logged in at 9am, edited ~100 different files. Many LSP inferior-processes running and emacs is currently sitting at 1 whole gigabyte resident memory.
What's more is that I would say this is a particularly light day for me and emacs.
I have literally never, never, not once ever had an issue with this much RAM and essentially turning gc off in emacs.
Yes, but which year ?
maybe emacs just doesn't use enough memory, relative to modern systems, for GC to be worth it.
(i do quit emacs at the end of each day, so that is a form of GC.)
You can be incorrect, or you can try it.