In my current game, for some reason the jellyfish enemies on Nix like to hang out near my base. They form an attack group, move towards the base and then just stop before they get there. After about 20-30 hours of this my UPS is starting to drop because of it. Unit updates are taking about 13ms, mainly due to Nix enemies.

I'm heading back to the planet now to clear everything out of my pollution cloud, but because pollution travels so far there this is pretty annoying to have to do

Small update. After clearing most of the jellyfish in my pollution cloud the unit updates are down to 1.2ms, and UPS is back to 60. So I guess I just have to set up more robust defenses and ensure that jellyfish spawners aren't hit by pollution at all going forward. A little annoying given how weak of an enemy they are. My previous defences were holding just fine, but I guess when they couldn't defeat my laser turrets they decided to launch an attack on my PC instead.

+1, unit updates dropped from 10+ to almost 0 (was about 40% of total update time in our game before we fix it) after killing all enemies on nix, a friend was lagging and deleting surface after surface as well as ennemies on different planets we found nix ennemies were the problem, for now we just kill them all every irl day with
/c local surface=game.surfaces["nix"] for key, entity in pairs(surface.find_entities_filtered({force="enemy"})) do entity.destroy() end
works fine, but there are still jellyfish being killed in production tab at half the rate than before so there are still nests in the dark (i didnt find any in explored areas but some were wandering alone), and pollution just goes further and further...)

Well, my "pollution workaround" helps, but the amount of inserters, etc., needed to keep it low is quite significant. After the research is done, I will wipe everything on that planet to get ups back. Maybe I'll let some very small factory, just so I can export some dark/antimatter.

I'll take a look at the pollution and the jellyfish, 2 separate problems.

I guess when they couldn't defeat my laser turrets they decided to launch an attack on my PC instead.
Has me rolling

I can give a +1 to this.

I just used some console commands to verify and my units updates dropped from 11 to almost nothing after killing all the nix enemies.
The pollution fix that you did recently - making the pollution gravitons, does seem to have helped though - at the very least, the pollution isn't spreading like crazy and spawning new chunks any more. Force revealing the map showed me just how much the old pollution system had revealed, and it's a lot. The current graviton pollution is much more contained, and that's good.

But the enemies.. there's something up with them and I'm a bit tired of having my game run at 45 UPS because of Nix.. (on the 'bright' side, I might finally have a reason to make some hydrogen bombs from Cerys. That might be fun :)

The previous system was creating pollution and never absorbing it. My suspicion is that it generated all those chunks, placed enemies on them, and now you have a very high number of enemies. I'm not sure if I have a great solution to that. maybe you can ungenerate certain chunks? or kill them all with a console command? be sure to backup your save before trying anything weird.

I don't think it would be anything intrinsic with the nix enemies, they're just reskinned biters that ignore collisions.

I'm sorry that this bug is causing troubles with your games.

I'm currently on a different modded planet, but as soon as I'm done there I am planning on heading back to Nix to commit some genocide (with spidertron so I don't just make the problem worse by generating new chunks. Just need to build the thing first and gear it up for war..). I'll let you know how much that helps. Planning on making saves and using commands to force reveal all the generated chunks to see where they are. I also just have 'show expansion candidate chunks' (the circle version) constantly enabled so that also helps me determine if the state of quantum enemies.

I already tried the console command to kill them all and that for sure brought the unit updates numbers down to good levels. Don't want to resort to console commands as my final solution unless I'm desperate though cause I like achievements.

Is there a way to ungenerate chunks without achievements getting disabled? (I guess I could uninstall and re-install metal and stars, but I don't really want to lose my ten stacks of modules productivity in all three tiers of modules.. Those were expensive and took a while to research..)

Hmm, them being reskined biters that ignore collision sounds like a good implementation.. That makes me think that it more has to do with sheer numbers, which yeah, there are a lot due to how pollution worked before..

Anyway, I'll let you know when I do my genocide and what that does to my UPS number. No worries about the trouble it's causing! I'm a game dev myself and I know very well that there are always bugs and issues that you simply cannot catch yourself.

The battle was long and (not so) fierce. The jellyfish died by the dozens - nay, by the hundreds! They whisper in the long night that if you listen closely, you may still hear the final screams of the jellyfish! But alas, they shall never again live on the shadowy planet. Freed from their presence, the factory grows even greater! [evil laugh goes here]

Ok yeah so I took out the spider and established world peace (no possible expansion chunks left, all nests killed). UPS problems fixed. Unit updates down to ~0.3 from ~10.7. During my genocide, I took photographic evidence of the evolved form of the jellyfish - the UPS eater. I've put these images into a google docs so you can view them (easiest way I could think of to share images since AFAIK you can't here on the mod forums :shrug: ). Anyway, here's said photographic evidence: https://docs.google.com/document/d/1Lhk_SVsMdnTBn_D5jzii18U1tC2VPRgF9MHjzbwzzmU/

Basically what happened was massive attack groups formed, but they never went in to attack, so they just grew larger and larger and larger. For some reason, I encountered the UPS eater more on the west side than on the east (also possible that I just hadn't noticed them in the east as I cleared the east first, then went counter clockwise). The most concerning encounters was when there was no nest nearby (or only 1 nest). There's no way that only 1 nest could've spawned such a massive attack group (unless it was just growing for a VERY long time, which I suspect it was).

Anyway, my UPS problems are fixed now, and hopefully with the pollution fix it won't happen to others. In the meantime, I now also know what was causing the massive UPS drop, even if not how the UPS eater formed.

Maybe a limit on the amount of enemies any given nest has spawned could be a fix? No idea if enemies know which nest they spawned from though. If they don't, that solution would just make each unit more intensive and thus make the problem worse..
My only guess as to why the attack groups didn't go in for an attack is because they absorbed pollution, then since they absorbed all the pollution in the chunk they lost sight of the potential attack target, and thus called off the attack. And that cycle just repeated over and over. No clue if that's a realistic possibility, but that's about the only thing I can think of with my limited knowledge..