You do not have a RAM problem. When "swaps" are zero, the computer had adequate RAM at the time of the test.
You have a hard drive issue shared by most owners of 21.5 inch iMacs since 2011 who do not opt for a faster storage option when ordering their computer:
Drives:
disk0 - APPLE HDD ST1000LM024 1.00 TB (Mechanical - 5400 RPM)
Internal SATA 3 Gigabit Serial ATA
For years Apple have installed slow 5400rpm, 3GBps mechanical drives in computers with fast 6GBps drive buses. That is a bottleneck. This makes startup and app launches slow, but other functions are fine.
As opening any iMac made after 2011 is very hard--the case is glued together--replacing the original drive with a faster mech drive or, better yet, a solid state drive, is very labor-intensive and therefore expensive. Many users have come up with a home-build work-about that helps.
They use a fast external USB drive to hold the system and most of the apps and set it as the boot volume. This requires:
- A USB3 external drive rated for SATA 6GBps speeds.
- A solid state drive (SSD) rated for SATA 6GBps speed.
You can't be sure you are getting these speeds from "name-brand" drives at the office superstore because they are not forthcoming about all the specs you need to know. Those drive are also built to go on sale every weekend, not for robust performance. Building from new parts (one USB3 external empty drive enclosure and one bare 6GBps drive) is super-easy and you know what you get.
Once the new drive is formatted (Disk Utility) and attached, you use cloning software to transfer the entire content of your current hard drive to the external one. I prefer Carbon Copy Cloner because it handles recreating the important factory-installed troubleshooting partitions without hassle. Then you use System Preferences > Startup Disk to set the external as your boot partition.
Why this works: You current set up can read/write data no faster than 3GBps, and a mech drive has low read/write speeds. These are your current r/w speeds from the report:
Write speed: 77 MB/s
Read speed: 78 MB/s
An external USB3 drive has a max transfer rate of up to 5GBps and the SSD reads and writes much faster than a mech drive. You should see your transfer rates go up by a factor of 5-7X. Real speeds in the vicinity of 400MBps should be attainable.
The original drive can stay where is it for extra storage.
Other than that, the EtreCheck report looks fairly clean but, again, you have a drive issue, not a RAM issue.
