So, there are some mods I used but I don't know how much they will impact your performance: http://www.nexusmods.com/newvegas/mods/49396/? New Vegas Save Cleaner, it removes reference IDs (litter lying around). It mostly puts items back in the starting positions. I don't know if it erases items of your collection. It did not for me. On my last run, it deleted ~5500 of those without me noticing bad effects (it also closes doors you opened so that the game does not have to save that too). http://www.nexusmods.com/newvegas/mods/37573/? I also use this even though I am not a big user of energy weapons. Basically, it makes ash and goo piles vanish after some time (not the quest ones of course) so that you don't have them staying permanently and bloating your save. Finally, I downloaded a 100% savegame someone made and tested my mods from there. With some simple commands, I changed my character back to what mine looked like. I have a fully modded game lag free now even though the 100% save is 15mb instead of my 12mb. I have decent FPS and I don't even know why. I did not litter anything on my recent playthroughs and it started lagging like hell nontheless.