So I have a 2009 Mac Pro quad core with 16GB of ram. In activity monitor, it's often some red, some yellow, and all blue - no green. Using up all 16GB - and even have 2-3 gigs of page outs. Here's what I am doing: I have 2 users logged in, and on one, it's just normal tasks like safari, mail, iTunes, etc. Normally it only takes like 4-6 gigs. On the second user, I have Roxio Titanium/TiVo transfer app transferring and converting shows from my TV to my mac. Does that really take up 16GB of ram doing that? I am surprised, I used to have 12GB and it was always enough. Crazy! I'm on lion 10.7.4 with an ATI 6870 graphics card and SSD drive.