I'm contemplating putting in a extra 16GB in my iMac i5/m290x machine bringing it up to 24 GB-- just because. Trouble is, the last memory upgrade I did was to my iMac 9,1, while it was running 10.6 (to 8 GB). There, it essentially let me compress eyeTV recordings in the background without interfering with the work I was doing the foreground. It made a huge difference. But now, I have a new machine that can compress what little video I record now (internet streaming is so much more convenient) in record time, and apple has, of course, changed how the kernel uses memory. I use the following apps at present. Abby Finereader iWorks stuff Open Office Xcode and associated compilers Draftsight Games-- currently slogging through Company of Heroes, but expect to play more advanced games after I finish the campaign. Safari, with many many tabs, Preview, with scanned books, Aperture I have a fusion drive, not an SSD, if that's the limiting factor. And I don't recall the memory pressure turning from green to yellow, much less red. So, how much of a waste of money would this be? Can I expect any performance improvement, or will 8GB serve me just as well?