Need Help Making a Decision on What to Do with Late 2012 iMac (EMC 2544)

[Muller0317]

Hello All!!
I recently been going back and forth in mind my on what to do with my late 2012 iMac EMC 2544. It is the 21.5" version with the 1TB Fusion Drive and 8GB of RAM. I recently bought a WD Blue 2TB SSD and a Satechi enclosure with USB-C connection and USB-C to USB cable. The issue I am having with the iMac is at moments it will run slow and freeze up, especially when unzipping RAR files. Also the iMac will randomly sound like a jet plane taking off and usually that's when I'm not even using it and it's sleeping or at least the display is off. I tried everything I could do to clean the fans from the outside and reset the PRAM and SMC. Also I wiped the computer clean and installed Mojave when it came out and didn't use any backups when I set it back up. I already have the kit from iFixit to remove the display and reseal it but I know this is a dangerous and tedious task. I have seen it done in person countless times but never actually did it myself.
I guess my question is: Should I split the Fusion Drive via Terminal and then install the OS and apps on the blade SSD part of the Fusion since this version has the 128GB blade SSD and then use the WD Blue with the enclosure and a USB-C to USB cable to store data? Or should I take the machine apart and install the WD Blue SSD into the slot where the HDD part of the Fusion Drive is? Also opening up the machine would give me the chance to really clean the fans and I would most likely add 16GB of RAM since I'm already inside. And yes I know if I were to upgrade the RAM I would have to practically take apart the entire machine since the RAM is on the back of the board. I'm just not sure what the best solution would be. I don't want to go the route of taking it all apart if that's not the best solution for my issues and won't give me any advantages. Thank you everyone in advance for your help and advice, I appreciate it.

Here are the links for everything I purchased:
Western Digital Blue 2TB SSD:
https://www.amazon.com/gp/product/B073SBRHH6/ref=ppx_yo_dt_b_asin_title_o03__o00_s00?ie=UTF8&psc=1

Satechi USB-C Enclosure:
https://www.amazon.com/gp/product/B01FWT2N3K/ref=ppx_yo_dt_b_asin_title_o02__o00_s00?ie=UTF8&psc=1

 

[Steve121178]

I have a late 2012 iMac with 1TB fusion drive since launch that's as good & efficient as the day it arrived. I always perform a clean install when a major update to macOS arrives & I've never had any kind of performance issues that other people seem to get.

I can't explain why you have so many issues if you performed a clean install. I presume you didn't import your data via Time Machine as there's no point in doing a clean install if you are going to bring all the issues back via a data restore.

 

[Fishrrman]

"Should I split the Fusion Drive via Terminal and then install the OS and apps on the blade SSD part of the Fusion since this version has the 128GB blade SSD and then use the WD Blue with the enclosure and a USB-C to USB cable to store data?"

If you can handle doing this, it's the path forward that I would recommend.

I believe the SSD portion of the fusion drive on that model is 128gb -- large enough to hold the OS, apps, and basic accounts (that don't hold "large libraries" of movies, music, and pictures).

Once done, the computer should boot and run "at the full speed" the internal SSD is capable of running. It should make the iMac much more responsive...

 

[Train]

That's exactly how I did it with my new iMac 27". I bought the 2TB Fusion Drive version to get the 128GB SSD. MacOS and all applications are on the 128 GB SSD, my photos are stored on an external 1 TB SSD. I don't use the internal HDD at all, on the contrary: The HDD is not even mounted at startup, so that it doesn't make any annoying noises (I used TinkerTool for that).

Of course I could have bought a model with a 256GB SSD, but I got the iMac very cheap at an online retailer, which unfortunately didn't offer BTO.

In my last iMac, which unfortunately broke down, I had a 1 TB SSD. It may be slightly less comfortable, but it's a lot cheaper. I am totally happy with my new setup.