Can RAM be added to my iMac Retina 21.5-inch, Late 2015

Hi Kristi,

Thanks for providing the EtreCheck report!

/Library/LaunchDaemons/com.intego.BackupAssistant.daemon.plist

/Library/LaunchAgents/com.intego.backupassistant.agent.plist

I see you have Intego software running. Mac computers do not need any sort of anti-virus software. Anti-virus can cause performance issues, security issues, and make macOS appear buggy. Your Mac is worse with these types of Apps installed.

In addition, Mac computers cannot get any traditional "viruses". They only area of concern is some malware, mostly adware, and it's easily avoidable. Do not install apps from unknown sources, and you'll be safe!

Here are some links that describe Apple's built-in malware protection, which are far superior:

•  macOS - Security - Apple
• Protecting against malware in macOS - Apple Support

To delete these components of Intego software, go to the Finder > Go > Go To Folder. Enter this path first:

/Library/LaunchDaemons/

And delete the Intego software. Do the same thing for this path:

/Library/LaunchAgents/

Hard drive too slow - The hard drive in this computer is too slow.

Performance:

System Load: 1.90 (1 min ago) 1.57 (5 min ago) 1.40 (15 min ago)

Nominal I/O usage: 0.98 MB/s

File system: 38.21 seconds

Write speed: 49 MB/s

Read speed: 60 MB/s

However, the main reason your iMac is slow is due to the 5400-rpm hard drive. While this hard disk found in your Mac is perfectly suited to light tasks, such as email and web browsing, but for more advanced tasks, and for users who want the maximum performance from their Mac, this hard drive does have its limitations. However, you can use an external SSD as your startup disk to run macOS and access your data. It will make your Mac 10 to 40 times faster for storage, and in turn, make your entire Mac much faster and even better.

To learn more, see:

Use an external SSD as your startup disk … - Apple Community.

Hope this helps!

Jack

Ok. I believe we need to proceed with an EtreCheck report. EtreCheck is a useful App to diagnose and identify issues, both hardware and software. It is trusted by many users. Please follow the steps outlined below:

1. Navigate to: https://etrecheck.com and get the free version of EtreCheckPro.
2. Download it. It is a free and trusted app. It is often recommended here on Apple Support Communities. 
3. Open EtreCheck, and before running the report, be sure to check “Allow full Drive Access” at the bottom of the EtreCheckPro window.
4. Run the report, and put it in a post, as shown here: How to use the Add Text Feature When Post… - Apple Community. We will then examine the report for issues in your Mac

Jack

I think the primary problem with your iMac is that it is running from a mechanical hard drive with an APFS disk (required under Catalina, Big Sur, Monterey), and it is the slowest mechanical drive (5400 rpm).

You can read about why this is slow here:

https://bombich.com/blog/2019/09/12/analysis-apfs-enumeration-performance-on-rotational-hard-drives

https://eshop.macsales.com/blog/43043-using-apfs-on-hdds-and-why-you-might-not-want-to/

Your 8 GB memory is minimal but ok. Increasing it will not help. What will transform your iMac is to replace the internal HDD with an SSD (solid state drive). I have the same 2015 iMac as you and had this same issue. For about $200 I had an Apple Authorized Service Provider replace the internal 1 TB HDD with a 1 TB SSD. What used to take 60 seconds now takes a second or two. It's like a new Mac.

Alternatively, you can set up your Mac to boot from an external SSD. This will not be as fast as an internal SSD but it will still be MUCH faster than what you have. There are different ways to do this, but the simplest might be to user a program like SuperDuper to clone your internal drive to an external SSD and then change your Startup Disk to be the external drive. I would first go to Monterey, by the way before doing either of these things.

By the way, when I took my iMac to the AASP, the technician said he could increase the memory but did not recommend it as it is difficult and involved and would cost a lot more. The replacing the HDD with an SSD is a complete game changer and this Mac works great now under Monterey, even with 8 GB memory.

If $200 sounds like too much to update a 2015 iMac, you can get new iMacs for as little as $1300 but you will want to spend more than that to get one that is nicely set up and won't be out of date in a few years. I recommend at least 16 GB memory and 1 TB internal SSD storage. My 2015 iMac is very lively and fast now, however.

Note added: I did not see Jack's reply before I posted this. I agree with everything he says.

Hello!

No, you cannot upgrade the Memory in your iMac (21.5-inch, Late 2015). Were you wanting to upgrade it due to performance issues?

Jack

Hi again!

None of the other LaunchAgents or LaunchDaemons listed necessarily need to be deleted. While they may be old, or no longer used, none are harmful being installed.

Jack