Wow, a lot of good information here-thanks, guys.
I had always heard that more RAM the better.
This is true, up to a point. If you have say, the bare minimum amount of RAM to run Yosemite (2GB), then clearly things are going to be tight. 4GB will work currently for most people. 8GB is better;
some can take advntage of that today, but most people will probably have a need for that amount later.
Beyond that, you see diminishing returns. 16GB and 32GB? Probably not useful to most users currently, unless you're running virtual machines that need their own RAM, or are being really intensive with data modeling, or heavy video editing with lots of files open.
The system was using up over 3.2Gb RAM on it's own so wouldn't upping it from 4 to 8GB RAM make any difference at all?
Yosemite is currently set up like most modern UNIX-like operating systems) to make use of as much RAM as is available, all of the time. If you throw 8GB at your system, you're probably going to see most of that used up as well.
What's happening is, OS X is filling up any RAM not directly used by applications for buffering and caching purposes. Frequently-used apps will have resources cached in RAM ready to go. Open files will be preloaded into RAM because it's faster to read off RAM than a spinning hard disk (and a tiny bit faster than SSD).
With my mother's Mini at 4Gb RAM memory clean was actually showing red (no free RAM) just with one window open in Safari.
Memory Clean is based on the false premise that you need to be using your RAM as little as possible. That might have been the case before Mavericks, but that's not how OS X works going from Mavericks on forward.
That said, Memory Clean isn't needed much anymore... most of the housekeeping functions it does are done far better by OS X. But, admitting that means no one will buy their product anymore. So, nice bright red graphics gives ill-informed people the illusion that the app is doing its job and they got their money's worth.
By and large, most of the "system optimizer" apps are snake oil. At best, they give people a placebo effect by doing what the OS does on its own already. At worst, some of them actually cause more problems than they supposedly solve.
Has anyone here had better luck using Chrome over Safari? Safari has been awful since Yosemite came out and I installed the latest update.
Chrome is worse. There, you actually WILL get memory leaks and RAM issues. If you're having problems now, I would avoid Chrome.
I'm wondering if the problem you're really having might be solved by a hard drive upgrade. I would look into an SSD upgrade. The difference between SSD and older hard drives is night and day.
