Overabundance of NPCs causes crash

[isra]

Out in the wasteland if I enter areas where there are too many enemies my game will become very choppy and eventually crash. I don't think it's a graphics issue as it occurs before they're even in sight, I'm pretty sure it's an AI thing. Some specific areas include Kaelyn's Bed & Breakfast outside of Vault 106 (which at level 20 spawns dozens of raiders) and near Arlington Library where dozens of Talon Company and Mirelurks spawn. Other than that, very few areas give me serious trouble. I have never had this problem with supermutants in any of the downtown areas even though they can get pretty numerous.

Right now the only way I can resolve the issue is to use the KillAll command before the game crashes.

 

Computer specs:

 

AMD Phenom 9950

Asus M3A79-T Deluxe

4GB Corsair 1066MHz RAM

Radeon HD 4870

Vista 32-Bit

 

I also use Marts Mutant Mod which changes spawns extensively. However I can't load my save games without it anymore as they crash and it's a great mod so I'd rather not be without it anyway.

Should my PC be able to handle 25+ spawns in these areas? If not, is there some way I can put a cap on the number of enemies which can spawn?

 

Thanks for any help.