Hi, I have a mid 2011 imac and upgraded to Maverick. It failed to run properly and the readout from Memory clean said I had 11 meg of RAM. I did the usual and removed programs, Memory clean gave me a gig back but that soon went. I bought and fitted 16 gig of RAM and all was well for a couple of days and now as I type it reads 4.28 gig with a very hesitant performance. What could be using 11 1/2 gig of RAM? Does anyone else have this issue. I am running no programs in the startup accessed through sys pref. Is this a known issue or is it just me?