USB SSD in a late 2012 iMac. Is it worth it?

[joe.pelayo]

Hi.

I use a Late 2012 iMac at work, which I love because of the screen, but has admittedly lagged behind. I have upgraded the RAM to 16GB but since it is not really mine I can not upgrade the internal 7200RPM HDD, which is the main bottleneck. Yesterday I got the idea of using an external USB SSD (not a flash drive) to install the OS. Is it worth it? Or would the USB interface pose as big of a bottleneck as the original HDD?

Thanks,
Joe.

 

[Juicy Box]

If your employer allows you to do it, it is totally worth it.

It will be like a night and day difference, and this is especially true if The Mac is on Catalina (or newer). APFS, which started with Mojave on Macs with OEM HDDs, run horribly unless you have a pure SSD. While true for Mohave, this seemed to have gotten a lot worse with Catalina.

You can get a Samsung T5 or T7, as they are popular on the forum, or get an internal SATA SSD, and an USB3 enclosure or USB/SATA adapter cable for cheaper than the Samsung.

You will get faster sequential speeds on the SSD than the HDD, but the random speeds will be many times faster on the SSD than the HDD.

Random speeds is what makes your Mac feel fast.

I highly recommend you do it if you employer allows it.

 

[joe.pelayo]

If your employer allows you to do it, it is totally worth it.

It will be like a night and day difference, and this is especially true if The Mac is on Catalina (or newer). APFS, which started with Mojave on Macs with OEM HDDs, run horribly unless you have a pure SSD. While true for Mohave, this seemed to have gotten a lot worse with Catalina.

You can get a Samsung T5 or T7, as they are popular on the forum, or get an internal SATA SSD, and an USB3 enclosure or USB/SATA adapter cable for cheaper than the Samsung.

You will get faster sequential speeds on the SSD than the HDD, but the random speeds will be many times faster on the SSD than the HDD.

Random speeds is what makes your Mac feel fast.

I highly recommend you do it if you employer allows it.

Thank you very much for your quick response. I am currently preparing to install Monterey in the machine (don't ask), which is really sluggish on the HDD. Luckily I already have at my disposal a USB enclosure and a 120GB SSD, so I believe I am all set.

Joe.

 

[Juicy Box]

Let us know in the thread if you see a performance difference with using an external SSD.

Another thing to keep in mind is that some external SSDs do not work well as a boot drive for MacOS. There's probably a list somewhere with these drives, but it is kinda rare. The only reason why I bring it up as if you have issues installing the operating system, it might be due to your external drive.

It's worth mentioning that the biggest downside of using an external USB SSD is that there is no TRIM support for macOS over USB. Thunderbolt has TRIM support, but USB does not.

This isn't a problem for most, probably. But, I personally have seen issues with the lack of TRIM. Without TRIM, you can see eventual slowdowns, especially with right speeds. Also, it could lead to premature failure of the SSD.

It all depends on how much you use it though (heavy or long term usage = potential problem sooner), as there have been plenty of people on the form that have been using external USB SSDs for years without issues.

 

[joe.pelayo]

Thank you all very much for your kind and useful responses.

I must say I am absolutely astonished with the amazing performance the machine now has with the new setup: a 120GB ADATA SSD inside of an ADATA external case, it is almost as if it were a new machine altogether! (Now I get why Apple moved away from Intel CPUs if it wanted better performance).

https://www.adata.com/es/consumer/503
https://www.adata.com/upload/downloadfile/Datasheet_XPG EX500 External Enclosure_EN_201702.pdf

Granted, the machine has limitations in other areas, such as the graphics department, but otherwise is awesome.

I am not sure how the lack of TRIM will affect it, but since I already had it laying around (removed from another machine that got a bigger SSD) I am delighted to see it working again and improving the performance of the iMac, thanks for the warning though! I'll report how much it lasts. The cool thing is that the system allows me to use the internal drive as well, so I can save and retrieve data from there and leave the SSD mostly for the operating system.

I installed Big Sur on it with the help of the "OpenCore Legacy Patcher" (the machine is officially limited to Catalina and couldn't install Monterey) and it works flawlessly. The only problem I found is that it fails to install Big Sur major updates: I am not sure if it is because there is a reboot involved and the machine kind of defaults to the internal drive, even though there is normally a boot menu that allows me to select the appropriate boot device. I wonder if this issue would go away if I reformat the internal drive to make it non bootable or something.

The upgrade made me so happy that I got a new keyboard for the machine (definitely recommend it):

https://www.logitech.com/en-us/products/keyboards/mx-keys-wireless-keyboard.920-009294.html

Thanks,
Joe.