So I just installed Mavericks, seemed like a normal installation no problems just took a long time. I'm using a mid-2010 MBP. It's done indexing and I'm left with a somewhat laggy Mac. Firstly, how can I view the RAM usage from just looking at the Activity Monitor app icon on my dock? Did they remove the feature? What do I do? Secondly, all the PNG files icons are the Preview app icon, not an actual preview of the picture as the icon of the file. I tried opening a PNG file and it said I didn't have permission, which is very weird because I was looking at the pic right before updating. Overall it seems laggy and I can't understand why. Is anyone having a similar issue? Any suggestions to fix it?