ok, so this is my second post on this problem that i have and i am kinda having this problem with most modpacks but i want to play POL the most so yeah.
now i have 8gb of ram, ~4 of them are allocated to minecraft (from the twitch launcher) and i am having some bad fps problems and lag spikes, at max i get like 20-15 fps max when im moving around my base and its is very spikie and it's very annoying.
my processor is an intel core i3-5005U 2.00GHz and i have integrated intel HD graphics 5500
my laptop should run this mod pack normally and with a sable fps but i dont know why it is doing this.
also, when im standing still i get like around 40-ish fps and it is kinda stable but it still has the lag spikes.
i've recently downloaded FTB vanilla+ which is a 1.7.10 modpack that has around 60ish mods and it still had the same problem that i have with POL also this doesnt happen with just mod packs it happens with normal minecraft too.
My computer is only a little better than yours (Intel Core i3-8130U 2.2GHZ, 6GB of Memory). I found that with Optifine, lowest video settings, and 4 GB of RAM, I can average 65-70 fps, with 60-80 mods.