Allo! for some odd reason, I've started having extremely annoying, frequent FPS drops lately. The game plays normally for 10 minutes, or an hour, or two hours, but then it starts to have drops which last 10-30 seconds (from smooth FPS to extremely stuttery 2-10 FPS), similar to the ones you have after saving but (obviously) much longer.
I did install new mods two days ago, however for two days worth of playing (12~ hours or so) it was fine, then today it started doing that.
I have all three DLCs.
Here is a list of the larger mods I have: Falskaar, wyrmstooth, Warzones, climates of tamriel, jswords, static mesh improvement mod, skyrim flora overhaul, skyUI, cloaks, immersive weapons, immersive armour, apocalypse spells, sperg, interesting NPCs, UFO, realistic lighting overhaul, CLO, and the 2K textures. (SKSE too of course)
They were all manually installed (this is about the fourth time I have skyrim installed on a computer with multiple mods and the first time with this problem).
My computer specs:
8 gb ram, i7 processor, nvidia 650m GPU. It's a laptop.
Things I've already done/checked:
heating issue - it's not one. stays at a stable 70 C, reaches 85~ C at the highest load. Laptop had new thermal paste applied 2 weeks ago and was checked for dust.
Drivers: all okay and not corrupt.
Windows memory problem: diagnostic came back with nothing.
gfx card in use: 650m, not the native intel 4k.
save games bloated: nope. I even used (after the problem started) a cleaner but it did not help.
When this happens: at random! in fact, I get -less- of it when I'm outside when the load is the largest. It happens anywhere, be it a tiny house in Whiterun, a dungeon, or the top of a mountain.
It is pretty irritating. I've tried lowering gfx settings heavily, but it did not work.
edit 1: if it's any help / a clue, this doesn't affect the menu when I press escape and want to save or change some settings, that is smooth.