Q: Do I need more RAM?

In most cases 12GB of RAM  is plenty, please look at Activity Monitor to see what processes are using all your RAM, in addition post an EtreCheck report of your system and we can look for obvious issues.

1. The actual max for your iMac is 32GB, but buy it from OWC only

2. 12GB is more than enough for almost all uses, post the report rkaufmann87 requested.

Green & occasionally yellow indicate that your RAM use is normal.

Green is when RAM is not under any pressure, Orange is when RAM is beings compressed.

Compressed RAM is better for performance than the alternative, swapping RAM to disk…

Red is shown when RAM is swapped to disk. Swapping means the RAM has been filled, compressed & still more memory is required, so some of it needs to be written to the disk, since the disk is a lot slower than RAM this can result tin the 'wait cursor' often called the 'spinning beach ball of death' or similar.  That swapped memory may be re-read from disk at some later point in time, meaning the slowness can continue.

See this for a better explanation of the details… (it still applies to 10.10)

http://arstechnica.com/apple/2013/10/os-x-10-9/17/#compressed-memory

If you are having issues with speed you may want to look at what type of disk you have - nowadays you may be comparing your 'slow Mac' to newer models that have SSD's. SSD's will improve reading & writing of data from storage, the OS spends a lot of time doing this and many people notice the speed improvement from an SSD compared to RAM upgrades.

Check what disk type you have…

Apple menu > Hold 'alt' on the keyboard > select System Information.

Find the SATA info under Hardware section, look at your disk's & check the 'Medium Type:' for the boot disk.

     Rotational = old style spinning disk

     Solid State = SSD.

Download and run Etrecheck.  Copy and paste the results into your reply. Etrecheck is a diagnostic tool that was developed by one of the most respected users here (and recommended by Apple Support personnel) in the ASC to help identify the more obvious culprits that can adversely affect a Mac's performance.

danielkyl wrote:

 

Thanks for the advice. The HDD is rotational. Though I do know that SSD is faster, but if adding more RAM helps, it will be more cost effective than buying a SSD i suppose.

It will be cheaper (if that is what you mean by cost effective) and it will also be nowhere as much of a speed improvement (possibly no improvement at all). I don't know about you but that hardly seems cost effective at all. The HDD is the slowest part of your Mac, adding Ram only helps when you run out of Ram (if you do) and then only until you use up the extra Ram

When you run out of RAM it gets written to the storage - your HDD is slow, a SSD is faster.

With a SSD swap is less of an issue - I rarely see the spinning wait cursor since fitting SSDs to Macs. The same task could wait for 10-30 seconds with a HDD.

I'd opt for SSD over more RAM for your Mac.

Your HDD is also more than 1/2 full - spinning disks perform slower the more data you put on them - it's basic laws of physics - the outer tracks of a disk can pass more data under the heads in comparison to the inner tracks. Disks have a limited rotation speed & they fill data from the outside towards the center for this very reason. Read up if you want more detail…

http://macperformanceguide.com/Storage-WhyYouNeedMoreThanYouNeed.html

P.S.

Macfuse has been superseded by OS X Fuse.

Consider removing it & installing OS X Fuse

https://osxfuse.github.io/

Also check your /etc/hosts file if you are not sure why you have 17 hosts defined…

cat /etc/hosts

…will show the file content in Terminal they may be normal if you are developing local test sites, but they may be abnormal if you didn't create them.

Learn how to actually use Activity Monitor, most of your ram being used is a good thing and perfectly normal How to use Activity Monitor - Apple Support

As noted above your hosts file may be hacked Fixing a hacked /etc/hosts file

Chrome is a resource hog, unless you really NEED it a better alternate browser is Firefox.

And finally.....do you realize that you haven't backed up in over 4 months?

SSD's are vastly faster than SSHD's

I am not sure about what everyone else has been telling you what to do.

Your Etrecheck report clearly shows you have a deficit of RAM as you have a large number of memory page outs.

Your HD is no where near full yet as a Mac can still operate fine as long as you do not fill it to capacity and leave, at least 15-20 GBs or more left on the hard drive.

Your memory page outs could indicate that you are using too many applications simultaneously. Try cutting back on the amount of open applications you use at one time.

12 GBs of memory should be plenty for common tasks.

My Mac is a late 2009 iMac with 16 GBs of RAM running both OS X 10.9.4 and OS X 10.9.5 Mavericks and I use graphics intensive apps like Photoshop and have no issues as long as I do not have a long list of other applications open concurrently.

Another thing that I would do,

Ditch ALL Googlewares. They are ALL a serious resource hogs on the OS X system.

https://support.google.com/chrome/answer/95319?hl=en

If you do not like Apple's Safari web browser, download, install and try Mozilla FireFox, instead.

The current, up-to-date version of FireFox is fully compatible with OS X and is regularly updated by the great developers of the Mozilla group.

I have, also, stopped using the Google search engine regularly (due to Google's privacy policies or lack thereof) and I now use DuckDuckGo as my default search engine.

Mac FUSE is obsolete and has been replaced by FUSE for OS X

https://osxfuse.github.io/

Make sure you updated all of your installed software and updated all connected third party device software and drivers?

Make sure  you have  updated all of the various web browser plugins you that have installed within your web browser?

Many Mac users forget to update all their software and update device driver and special device software and update any web browser plugins that they have installed previously.