According to a memory snapshot from Firefox 126 devtools, with uBlock Origin, immediately after a fresh page load:
old.reddit.com: 52.54 mb
new.reddit.com: 93.48 mb
lemmy.world: 54.44 mb
old.lemmy.world: 20.25 mb
I imagine both versions of Reddit would be worse without the adblocker. There are multiple frontends for Lemmy, and I did not test them all. Other browsers might differ slightly.
Thanks for asking! I’m using a T440 thinkpad with 8gbs of ram. I’m not planing to upgrade the specs as it is my backup linux machine. I would like to be able to use it in the optimal way possible.
Pretty much anything, from your Desktop Environment to the simplest application running in the background, will have way more of an impact than pretty much any semistatic website.
I'm curious, what do you mean with "in the optimal way possible"? Are you constantly maxing out your RAM already, and if so, how?