It's recommended that Monterey is the best suited for My late 2017 Retina 4K 21.5 iMac,
as later macOS operating systems run slower on my particular iMac.
My iMac is already running slow and get's hung up in unbearable ways, so I'm not in hurry to update.
Anyway - I read that perhaps using an external startup disk could really speed things up...
Any advice on this, besides a new computer ?
Cheers
iMac 21.5″ 4K, macOS 12.7
I assume you mean the iMac (Retina 4K, 21.5-inch, 2017) which came out in June 2017.
Yur Mac cannot run anything higher than Ventura. For now, Ventura is one of the "most recent three" – but if Apple sticks to the same release schedule that they have for the past ten years, Ventura will fall off of that list some time in September, October, or November.
If your iMac has
that drive is very likely a cause of slowness. The 1 TB hard drive uses a 2.5" 5400 rpm notebook drive mechanism, and the 1 TB Fusion Drive combines that mechanism with a skimpy, inadequate amount of SSD storage.
You could add an external SSD, using a USB-A (USB 3.0), USB-C (USB 3.1 Gen 2), or Thunderbolt 3 connection. A couple of examples of mid-priced SSDs would be:
Making an external SSD your startup disk would help with the time it takes to start up the Mac, and with the time it takes to launch applications, and might make the Mac feel "snappier" in other ways.
But it wouldn't let you do anything to upgrade past Ventura.
I have a 2017 iMac running Ventura and it's the best system I've ever run on that iMac.
If your current iMac is working OK you can clone your internal drive from it to the external SSD by following this User Tip: Using Carbon Copy Cloner to Make a Bootable Clone of an Intel Mac - Apple Community
The recommendation to get an OWC (MacSales.com) external SSD is right on. If budget is a concern you might try what I did:
I was able to get 500 Mbs read and write from it and it booted in about the same time as my internal SSD and I didn't really notice much changes in performance. The speed of the internal SSD was about 4 times faster when tested.
It all depends how much speed is important to you.
Just some food for thought.
You might also take a look at this guidance:
Use an external SSD as your startup disk … - Apple Community (Thanks, Jack-19.)
Have a look at and follow the directions in the user tip written by Jack-19.
Use an external SSD as your startup disk … - Apple Community
You can use most any TB/USB-C SSD, but I recommend OWC or Crucial.
D.I. Johnson wrote:
You might also take a look at this guidance:
Use an external SSD as your startup disk … - Apple Community (Thanks, Jack-19.)
That is excellent advice which I have taken personally. One thing, though. Following yesterday's change to macOS versions, I now have to plug in my external SSD and restart my Mac from it ..... then update the macOS on my external SSD if I want it to stay 'current'.
Or is such a procedure unnecessary?
Before you go to the expense and effort of getting a bootable external SSD you should verify that your problem is not related to any of the 3rd party software that you've installed. That being said please download and run Etrecheck. The free version is sufficient.
Copy and paste the results into your reply. Etrecheck is a diagnostic tool that was developed by one of the most respected users here in the ASC and recommended by Apple Support to provide a snapshot of the system and help identify the more obvious culprits that can adversely affect a Mac's performance.
Copy the report
and after clicking on the Reply button use the Additional Text button to paste the report in your reply.
Check Etrecheck's Privacy settings and make sure the checkbox for full disk access before running:
Then we can examine the report and see if we can determine the cause of the problem.
Yes, that is correct. To keep the OS on your external startup drive current you would have to update it just as you would if booting from the internal drive. It is still a necessary procedure.
Servant of Cats wrote:
You could add an external SSD, using a USB-A (USB 3.0), USB-C (USB 3.1 Gen 2), or Thunderbolt 3 connection.
I would vote for an external USB 3.1 Gen 2 (10 Gbps) SSD connected to one of the USB-C ports on this iMac. It will beat the 5 Gbps speed of the USB 3.0 (USB-A) ports and be considerably less expensive than Thunderbolt 3.
The 1TB OWC Envoy SSD that you linked is a pretty impressive drive and comes at a good price.
D.I. Johnson wrote:
Yes, that is correct. To keep the OS on your external startup drive current you would have to update it just as you would if booting from the internal drive. It is still a necessary procedure.
Many thanks. The job has now been done! 😄
I suspect that if the OP, Michael Hoerner, was to invest in a new 24 inch iMac he would be truly amazed at how quickly everything just 'worked'!
Use External Hard Drive as Startup disk for 2017 21.5 iMac ?
