Im playing campaign right now and task manager says its only using 3.6gb or ram. Then I keep getting an error saying windows is low on memory so cod has to close. I have windows 8.1 x64. And this game is supposed to use at least 6 gigs of ram.
Do you have page file disabled? I used to do that on my SSD(128gb) cause it frees up 3-4gb of space but your pc needs to use more ram. I used to get that same error playing TOR. Had to turn it back on so i would stop getting the error.