Working away at the Mesogea mod, I have hit a recurrent CTD on the current plugin. The main landmass and vegetation etc is in an ESM of quite some size, 900MB but this works perfectly well continously, for hours on end without a single hiccup.

I have made a lot of progress in a small world city district and all again was going extremely well with only one CTD in two weeks. Hmm, good going.
Now this is where I "think" I have hit a wall, or have I?

I have been adding NPC's and packages, there must be about fifty NPCs going about their everday. No scripts, just packages, with about 4-6 packages per NPC. Not all NPC's are out and about at any one time, some sleep, some are awake. As I said, this is in a small world space similar to a city district of the Imperial city kind of thing. It seems I added another four NPC's and ran the plugin, but got a regular CTD. I tried Vanilla and it ran ok, I re ran the mod and it CTD's every time I wait a few hours in the affected worldspace or wander about for a few minutes.

My questions are:

1. Is there a maximum number of NPCs that the game can handle? Oblivion Vanilla has hundreds and the game goes on fine, so are these NPCs of mine just too many for one place, for one set of cells for the game to cope with?

2. Is out of sight out of game mind. If I call a halt to this area now and close it down, add in the teleport doors to the rest of the city and move on to another small world space will things kind of reset there? Will these NPCs and packages only roll when my character is within a certain worldspace set of cells?

3. Would too many NPCs not just cause massive lag rather than a CTD? Or does the game reach critical mass as it were, without the fps grinding to a halt?

I re ran the game with a day old save of the plugin (I save every day and pack them away in archive so I can step back through errors to find the last secure plugin. The CTD does not happen. There are less NPCs but the same quantity of clutter etc.

What causes the most issues?

NPC quantity.
Packages running in a space
Items

Or am I missing something here?

Hi Karith,
From what I understand there are limits when it comes to NPCs AI and the Oblivion Engine. The limit for NPCs in one area is typically just under 20, estimates are usually between 16-18 more or less. This is the number of NPCs who can be processing AI in the same space.

There are ways to reduce the effect of this limit on city spaces. One way is to check the "No Low Level Processing" flag on any NPCs who are predominantly homebodies. This will stop them from processing AI unless the player is in the near vicinity.

Another place to cutback some AI usage is in guard posts. Always use one guard not two at your posts to cut your numbers. It's an easy spot to save some AI slots.

If you look at the towns in Oblivion they typically have two guards standing post (one at each gate) and one or two patrolling, then about ten general NPCs. The majority of their NPCs are in interiors and set to "No Low Level Processing" so they only run their routines when the player gets in that interior.

I think the answer to number 2 is no, the game does not stop keeping track of one worldspace just because you enter another. Not 100% sure, but I believe unless marked flagged to "No Low Level Processing" the NPCs will continue to run their AI, but the global limit for the overall game is much higher than the 16-18 in one area.

If your NPC quantity is high enough to stretch your game passed functional a CTD is likely eminent. I think your trouble is just too many, I ran into trouble around Sance Tor when I got to about 28 and if you have around 50 you're beyond that already. RST adds over 200 NPCs though, and I have found as long as I limit the number running in one area at once the issues are nil.

Hang in there, this is not a wall by any stretch. You just have to shoot for the illusion of populated rather than actual populace and shift some things around. Good Luck! :foodndrink:

That looks to be about the size of it then, I need to start adjusting things a bit I think. I have about five houses yet to populate, so what I intend to do is strip down the AI on some of the characters, rather than have five or six packages I can knock them down to two in some cases.

I just counted them up, there are 41 NPCs at this moment, all running packages in the agaria world space thats made of about 16 cells, with about 18 attached interiors. All of these NPCs are running without the low level processing box ticked, so the game is trying to process all of them. No wonder it cracked!

Is that the culprit then, do you think?

Sounds like your most likely culprit, do some adjusting and you should see much better performance. :goodjob:

One thing you can do in addition to flagging their low level processing off, is simplify the AI of those who stay in interiors. Maybe a basic wander package with a sleep pack for night hours. Since many players do not trespass and will never see complex routines it's a place you can trim down. :foodndrink: