Mid 2011 iMac Freezing/Crashing

The first thing you should do is get a full and current backup of your boot drive. You don't have Time Machine enabled but do you have some other type of backup enabled?

Give this a try: boot into Safe Mode according to How to use safe mode on your Mac and test to see if the problem persists. Reboot normally and test again.

NOTE 1: Safe Mode boot can take up to 3 - 5 minutes as it's doing the following; 

• Verifies your startup disk and attempts to repair directory issues, if needed

• Loads only required kernel extensions (prevents 3rd party kernel/extensions from loading)

• Prevents Startup Items and Login Items from opening automatically

• Disables user-installed fonts 

• Deletes font caches, kernel cache, and other system cache files

NOTE 2: if you have a wireless keyboard with rechargeable batteries connect it with its charging cable before booting into Safe Mode. This makes it act as a wired keyboard as will insure a successful boot into Safe Mode.

Hello!

It sounds like there's some deep underlying hardware issues, and since your iMac is obsolete, as classified by Apple, I would recommend you look into a new Mac: Buy Mac - Apple, unfortunately.

Jack

I understand your comment, but I am just going to continue on with this, besides this new crashing this thing is amazingly quick and when high sierra becomes too old I will consider a new one.

You could upload your EtreCheck report for evaluation, which could help: How to use the Add Text Feature When Post… - Apple Community.

However, macOS High Sierra is rather old. It hasn't received a security update in over 2-years, is 5-generations behind the current version, and most major browsers soon won't be supporting it.

Jack

icy176 wrote:

The ram is stock apple ram and samsung ram added. I think I may install macOS on the passport as it isn't a big data holder for me and these old apple hard drives haven't aged well.

Mixing RAM like that is usually not recommended. It could result in odd behaviors. Apple computers accept a fairly narrow range of only highest quality RAM. If your problems are RAM related, replacing the hard drive won't help.

Booting from an external drive would be a good thing to try because your internal hard drive may be failing based on the very slow write speeds versus read speeds reported in Etrecheck. Both should be 100 MB/s at least. If you try the external boot drive, get an SSD for best performance.

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

A 2011 iMac is likely near end of life, regardless of how attached you are to it! Getting more than 5-7 years from a computer is a bonus, and more than 10 years is unusual. I am familiar with this as I have a 2011 MacBook Air still working (High Sierra), 2013 MacBook Air (Big Sur) still working, and a 2015 iMac (Monterey) still working. I like keeping these vintage machines running well, but sometimes one must replace parts (which gets expensive the older they get) and sometimes one needs to let a worn out computer go. Also for important things, like taxes, I use a modern Mac.

We had a 2008 iMac running well until a few months ago when the power supply failed, so that one had to be recycled, the cost of getting and replacing the power supply would exceed the cost of a new iMac.

Keep in mind that the very compact Macs like laptops and iMacs have electronics installed in very tight physical spaces and they thus experience considerable change in temperature over time, during operation. This wears out the electronics, as solder joints expand and contract with temperature and eventually stop working well, over time.

The hard drive is having issues:

Performance:

System Load: 1.65 (1 min ago) 1.39 (5 min ago) 0.92 (15 min ago)

Nominal I/O usage: 0.01 MB/s

File system: 28.26 seconds

Write speed: 48 MB/s 👈🏻

Read speed: 114 MB/s

Write speeds should be closer to 100MB/sec

What memory make/model did you use when you upgraded the RAM? Memory comes up in Diagnostics a bit too much for my comfort.

Do things improve if you disconnect the WD Passport drive?

When you hear this clicking sound, does it sound mechanical or from the speakers of the Mac?

Have you already performed an erase and reinstall of macOS?

Jack