So, I have seen a lot of people complaining about their frame rate on BO2 going good for about a minute, then dropping really low for about 3-5 seconds. Even when they have excellent systems.
So, right now, I'll guide you through what I did to stop my frame rate stutter.
1. If you are running windows vista like me ( I know, Vista is shit) Turn of Aero Glass, set it to windows Classic, i know it looks like crap, but you can easily turn it back on whenever, it takes 10 seconds.
2. Turn every single graphic option to the lowest possible, everything else to the "No" option
3. Put the game into windowed (border) and set the Res to 800x600, or if you have a massive screen, like 1900x1200, out it into 1280x720 (if you can) Pretty muc, put it to the lowest res the game will allow you to.
4. Now here is where it gets difficult. You must go to control panel, and adjust the page file of the HDD the game is installed on, should be the C:\ Usually, the min. size is 200MB, and the max is 4096MB, set the min. to 200, and the max to 4000, because normally the max would be around 3800 if you have never touched it before.
5. Now, when running the game, after you open it, let it load, click online, and wait for it to load again. (for some poeple it might freeze frou about 10 seconds, it happens to me, don't worry about it.
6. After it's done loading, hit ctrl+alt+del and open your Task Mananger, go to the apps tab, right click the Black ops 2 app, and click, "go to process", after that, right click the highlighted process, and set the priority to Above normal. (NEVER SET IT HIGHER, otherwise you may get bluescreen, a harmless one, but it will crash your computer.
You should be fine now, do steps 5 and 6 everytime you open open the game, and your stuttering should stop in-game.
I did this and i no longer have frame. and with a bit of editing magic, you can still make the game look good (recorded with fraps, in half-size, at res 800x600 with lowest graphics.)