External SSD System Drive for 2017 21.5" Retina 4K iMac

[Mase53]

Looking for verification prior to an upgrade purchase. My 2017 iMac has been continually slowing down over the past year or so. I've run CleanMyMac on the system with little change in performance. The system is currently running BigSur 11.6.1 and has 8 GB RAM and a 1TB conventional hard drive. The system is very slow to boot and launching apps is also a slow process. I'm considering purchasing an external SSD to use as the system drive. I've reviewed many of the threads covering this approach and it looks like it should work but with things changing constantly I wanted to verify my selection of products to undertaking this upgrade.

I'm looking to purchase a Thunderbolt enclosure from Sabrent (https://www.amazon.com/Thunderbolt-...re-EC-T3NS/dp/B08FT59SB6?ref_=ast_sto_dp&th=1) along with a Samsung NVMe 1TB SSD (https://www.amazon.com/gp/product/B07MFZY2F2/ref=ox_sc_act_title_1?smid=ATVPDKIKX0DER&psc=1). Looking for any experience and/or recommendations concerning this approach.

Appreciate the help...

Mase

 

[dictoresno]

There’s lots of info about the Samsungs being finicky with macs, but I don’t know if that’s only when I stalled internally in a PCIe slot or if it applied to externally booted drives.

That being said, I just purchased an external NVMe enclosure and drive to install inside my iMac. I used the enclosure to pre-format and install Ventura on it before installation. This is the enclosure and drive I ended up purchasing after seeing dozens of threads regarding what works best. Also, I used the USB-C version with a USB-C to USB 3.1 adapter. It ran fine and was fast enough.

SABRENT USB 3.2 10Gbps Type C... https://www.amazon.com/dp/B08RVC6F9Y?ref=ppx_pop_mob_ap_share

WD_BLACK 2TB SN770 NVMe Internal... https://www.amazon.com/dp/B09QV5KJHV?ref=ppx_pop_mob_ap_share

 

[Mase53]

dictoresno,

Thanks for the feedback. I'm not totally fixed on the Samsung SSD. The WD_Black and Samsung are the same price on Amazon, with the WD_Black listing better potential maximum performance. I'll probably switch to the WD_Black based on your comments.

Any comments on how this change will impact the overall performance of my iMac?

Mase

 

[Grubster]

I was running my 2015 iMac on a SSD NVMe via USB A adapter for months, it worked fine. I guess the thunderbolt should help boost it further. I was using the SSK kit to make a USB C Drive.

I also keep a spare USB 512 SSD with Monterey installed on another SSK external NVME handy. You can plug that in to any machine I get and boot from it and be up and running in no time. It's nice to use to test laptops and such and boot in a pinch if you have problems.

 

[Mase53]

I was running my 2015 iMac on a SSD NVMe via USB A adapter for months, it worked fine. I guess the thunderbolt should help boost it further. I was using the SSK kit to make a USB C Drive.

I also keep a spare USB 512 SSD with Monterey installed on another SSK external NVME handy. You can plug that in to any machine I get and boot from it and be up and running in no time. It's nice to use to test laptops and such and boot in a pinch if you have problems.

Thanks for the input. I would still like to get input from someone with experience with the soecific enclosure and drive I'm considering.

Mase

 

[Grubster]

Thanks for the input. I would still like to get input from someone with experience with the soecific enclosure and drive I'm considering.

Mase, my understanding is the issues with ssd nvme and potential sleep wake issues only occur when installed internally. Externally either drive should be fine. I can tell you my drive was western digital. as far as the Sabrent enclosure, I would just buy it and return if a problem And switch to usb-c. Or buy 2 nclosures and return the other one after you test it.

 

[Fishrrman]

OP wrote:
"The system is currently running BigSur 11.6.1 and has 8 GB RAM and a 1TB conventional hard drive"

Well, there's your answer, right there.
See "conventional hard drive"?
As in a "platter-based, spinning hard drive"?
That's NEVER going to be fast.

Since we know what the problem is, let's solve it.

My advice is that you DO NOT buy a thunderbolt enclosure.

Instead, get a USB3.1 gen2 drive.
The Samsung T7 "Shield" would be fine, on sale at a good price:

SAMSUNG T7 Shield 1TB, Portable SSD, up to 1050MB/s, USB 3.2 Gen2, Rugged, IP65 Rated, for Photographers, Content Creators and Gaming, External Solid State Drive (MU-PE1T0R/AM, 2022), Blue

Samsung T7 Shield Portable SSD delivers high performance on-the-go, not matter the terrain. It has an IP65 rating for water** and dust* resistance, with Dynamic Thermal Guard to manage heat control. Transfer huge files instantly. USB 3.2 Gen 2 and PCIe® NVMe™ achieve soaring sequential read/write...

www.amazon.com

Plug that into one of the USBc ports on the back.
Then use disk utility to erase it to APFS, GUID partition format.
Don't worry about the Samsung software -- you don't need it.

Then use SuperDuper to "clone" the contents of the HDD to the new SSD.
SuperDuper is FREE to use for this purpose, and you can download it by clicking here:

https://www.shirt-pocket.com/mint/pepper/orderedlist/downloads/download.php?file=https%3A//www.shirt-pocket.com/downloads/SuperDuper%21.dmg

Once the clone is done, go to the startup disk preference pane and set the SSD to be the new boot drive.

The T7 Shield will give you read speeds around 850-900MBps -- very good.
What kind of read speeds are you getting NOW?
(If you don't know, use the free BlackMagic Speed Test utility to find out)

Good luck.

 

[Grubster]

OP wrote:
"The system is currently running BigSur 11.6.1 and has 8 GB RAM and a 1TB conventional hard drive"

Well, there's your answer, right there.
See "conventional hard drive"?
As in a "platter-based, spinning hard drive"?
That's NEVER going to be fast.

Since we know what the problem is, let's solve it.

My advice is that you DO NOT buy a thunderbolt enclosure.

Instead, get a USB3.1 gen2 drive.
The Samsung T7 "Shield" would be fine, on sale at a good price:

SAMSUNG T7 Shield 1TB, Portable SSD, up to 1050MB/s, USB 3.2 Gen2, Rugged, IP65 Rated, for Photographers, Content Creators and Gaming, External Solid State Drive (MU-PE1T0R/AM, 2022), Blue

Samsung T7 Shield Portable SSD delivers high performance on-the-go, not matter the terrain. It has an IP65 rating for water** and dust* resistance, with Dynamic Thermal Guard to manage heat control. Transfer huge files instantly. USB 3.2 Gen 2 and PCIe® NVMe™ achieve soaring sequential read/write...

www.amazon.com

Plug that into one of the USBc ports on the back.
Then use disk utility to erase it to APFS, GUID partition format.
Don't worry about the Samsung software -- you don't need it.

Then use SuperDuper to "clone" the contents of the HDD to the new SSD.
SuperDuper is FREE to use for this purpose, and you can download it by clicking here:

https://www.shirt-pocket.com/mint/pepper/orderedlist/downloads/download.php?file=https%3A//www.shirt-pocket.com/downloads/SuperDuper%21.dmg

Once the clone is done, go to the startup disk preference pane and set the SSD to be the new boot drive.

The T7 Shield will give you read speeds around 850-900MBps -- very good.
What kind of read speeds are you getting NOW?
(If you don't know, use the free BlackMagic Speed Test utility to find out)

Good luck.

I would say at $79.99 that is a great deal! Normally you would have to buy a NVMe SSD + Enclosure and it would probably be the same or more money!

 

[Mase53]

OP wrote:
"The system is currently running BigSur 11.6.1 and has 8 GB RAM and a 1TB conventional hard drive"

Well, there's your answer, right there.
See "conventional hard drive"?
As in a "platter-based, spinning hard drive"?
That's NEVER going to be fast.

Since we know what the problem is, let's solve it.

My advice is that you DO NOT buy a thunderbolt enclosure.

Instead, get a USB3.1 gen2 drive.
The Samsung T7 "Shield" would be fine, on sale at a good price:

SAMSUNG T7 Shield 1TB, Portable SSD, up to 1050MB/s, USB 3.2 Gen2, Rugged, IP65 Rated, for Photographers, Content Creators and Gaming, External Solid State Drive (MU-PE1T0R/AM, 2022), Blue

Samsung T7 Shield Portable SSD delivers high performance on-the-go, not matter the terrain. It has an IP65 rating for water** and dust* resistance, with Dynamic Thermal Guard to manage heat control. Transfer huge files instantly. USB 3.2 Gen 2 and PCIe® NVMe™ achieve soaring sequential read/write...

www.amazon.com

Plug that into one of the USBc ports on the back.
Then use disk utility to erase it to APFS, GUID partition format.
Don't worry about the Samsung software -- you don't need it.

Then use SuperDuper to "clone" the contents of the HDD to the new SSD.
SuperDuper is FREE to use for this purpose, and you can download it by clicking here:

https://www.shirt-pocket.com/mint/pepper/orderedlist/downloads/download.php?file=https%3A//www.shirt-pocket.com/downloads/SuperDuper%21.dmg

Once the clone is done, go to the startup disk preference pane and set the SSD to be the new boot drive.

The T7 Shield will give you read speeds around 850-900MBps -- very good.
What kind of read speeds are you getting NOW?
(If you don't know, use the free BlackMagic Speed Test utility to find out)

Good luck.

Fishrrman,

Thanks for the input, I agree the HDD is my main problem.

Mase

 

[Mase53]

Fishrrman,

Thanks for the input, I agree the HDD is my main problem.

Mase

Finally I installed the Thunderbolt SSD Drive using a WD_BLACK 1TB SN770 NVMe. I'm using the Sabrent Thunderbolt 3 Enclosure. I installed Monterey 12.6.3 on the external drive and set that up as my boot drive. The results have been nothing short of fantastic.

I ran the Blackmagic Disk Speed Test with the original internal HDD and got these results.

Following the installation of the Thunderbolt SSD my results changed to this for the external drive.

The system responsiveness has been outstanding. A relatively inexpensive upgrade (~$150 total) for a huge improvement in performance.

Mase

 

[lcharlton4]

Great Advice, just used SuperDuper to clone and the Sabrent Thunderbolt with WD SN 770 on a 2017 imac 21.5 and wow! We went from basically an unusable computer to this... Thanks to everyone here.

 

[Raincoaster]

This is a really helpful thread - wondering if anyone can share if there are any updates on this approach? My 2017 iMac 27" just had the hard drive finally give out and I'm thinking this is a good way for me to get the thing back up and running. Looks like the Sabrent enclosure is still available. Can anyone recommend a 3TB compatible drive? The ones used by others in this thread don't go up quite that high and I would like to mirror the current 3TB drive I have (and have all my backups on). Advice very much welcomed!

 

[Fishrrman]

Rain --

A 2017 iMac has USB3.1 gen2 (USBc) ports on the back.
USB3.1 gen2 will support read speeds up around 900+/- MBps.

I'd suggest a Crucial X9. Very small, runs fast.
Comes in 1tb, 2tb, and I think 4tb.

Format it to APFS.
The use either SuperDuper or CarbonCopyCloner to clone from the internal to the USB SSD.
Then set it to be the boot drive using the Startup Disk pref pane.

Do this, and I predict you'll come back here and tell us you're quite pleased with the performance.
(I'd suggest "AJA System Test Lite" to check the speeds)

 

[Raincoaster]

Thank you! I will give this a look - it looks more affordable and I like only having one piece of hardware to work this up.

Two questions (more or less!):

1) I thought I had a Thunderbolt port? Per this Apple Support page, it says I do, but it also says what you are saying about USB3.1 gen2? Is there something about the ports on this computer that preclude TB speed?

2) You mention using SuperDuper or CarbonCopyCloner to clone from the internal drive to the USB SSD. My iMac won't boot ("disk2s1: I/O error" and "AMFI: Denying core dump for pid XXX..." amongst others in the boot up failure). How would I do this if I can't get the system started? I do have a Time Machine backup, a CarbonCopyCloner backup, and a BackBlaze backup, as well as the MacBook Air I'm typing this from right now to work with. I am thinking I might install Ventura from the MBA to the drive, start the iMac in target mode (at least that's what I think I'm supposed to do) and then restore my data from the Time Machine backup?

Thanks again for your help!

Edit: Is this the right Crucial drive you're recommending? I see this one has USB 3.2 in its specifications, will that be a problem? I'm trying to squeeze all I can from this system until I can figure out what to get in replacement. Would love a straight up 27" iMac but obviously that's not an option! I also see there's an X9 Pro and an X9 Pro for Mac. Am I right that these are basically the same drives but in different cases? Performance looks the same?

 

[Fishrrman]

Rain -

Since you already have a CCC backup, I'd do this:

First, FORGET ABOUT thunderbolt. Expensive and not really worth it, in my opinion.
Get a USB3.1 gen2 drive, as I suggested above.

Next, once you have the new SSD "in hand"...

The CCC cloned backup you have now should be bootable.
Have you not tried booting from it?
If not, WHY NOT?

Connect it.
Hold down the option key and press the power on button.
KEEP HOLDING DOWN the option key until the startup manager appears.
Do you see the CCC backup?
If so, click on it and hit return.

Do you get a good boot to the finder?

If you get that far, format the SSD to:
High Sierra and earlier -- HFS+ (Mac OS extended, journaling enabled, GUID partition format)
Mojave and later -- APFS (GUID partition format).

Once it's on the desktop, and you're booted from the CCC clone, all you have to do is "clone the contents of the backup" TO the SSD.

Then set the SSD to be the new startup drive.
And of course, TEST IT after you've done so.

This isn't [quite] rocket science.
If a dummy like me can do it, YOU can do it.

Good luck.

There are alternative routes.
For example, you could boot to INTERNET recovery (command-OPTION-R), then install a recent version of the OS, and then restore from the CCC backup using setup assistant on the brand-new OS.

This is a decision YOU have to make first.

 

[Raincoaster]

Thanks for these suggestions! At first, I didn't think to try to boot off the drive (too many other things going on along with a dead computer). So I followed your instructions but the drive does not show up in the menu (just the old Macintosh HD), which led me here to see why it might not be appearing.

The drive I have my clone on is a 3TB G-Drive SATA so I wonder if the combination of a too-big drive, a maybe too-old iMac, and a Western Digital product may all be conspiring against me. I am going to dig through their suggestion list and see if I can find something that works. Will update when I have more to report.

I appreciate your help!

 

[Fishrrman]

Raincoaster --

You still have options but I won't be able to post any more until tomorrow.

 

[Raincoaster]

Raincoaster --

You still have options but I won't be able to post any more until tomorrow.

No worries, my next step is to order the drive you have suggested!

 

[drrich2]

Hi. I had a similar situation; 2017 iMac with failing Fusion drive, bought a Samsung T7 Shield 4-TB SSD (USB-C, not Thunderbolt) to use as an external startup disk. This was late last year, IIRC, so I don't recall all the details. I had a Western Digital external HDD which held my Carbon Copy Cloner backup. I thought I could simply copy that onto my T7 Shield, make the T7 the startup disk, and go.

As I said, I don't recall all the ways and wherefores. Here's the bottom line on what went down.

1.) I thought Carbon Copy Cloner made bootable clones of a disk on demand. That wasn't working for me. CCC has a page discussing the issue.

2.) So what I needed to do was hook my T7 Shield external SSD to my old 2017 MacBook (same year as my iMac but not the same computer) and use Mac OS Disk Utility to format it - checked just now and it's APFS format.

3.) I then downloaded the installer for Ventura (the latest Mac OS version officially approved for my iMac) and installed it onto my T7 Shield.

4.) I then plugged the T7 Shield into a USB-C port on my iMac and made it the Start Up Disk, and rebooted.

5.) My memory is sketchy here, but I used the Carbon Copy Cloner backup on the Western Digital hard disk drive as the source to migrate info. to the T7 Shield. Can't remember if I used Migration Assistant or not.

Now my old iMac works much like it did before, only it 'feels' a little snappier.

This saved me from needing to buy a new desktop Mac right away.

So, if you manage to easier make a bootable clone and that works out, great! But just in case it doesn't, there is another way.

 

[Fishrrman]

Rain --

Can you boot the iMac into INTERNET recovery?
This is NOT THE SAME AS "the recovery partition".

The iMac should be powered down, all the way off. Pull the plug from the wall if you have to.

Then...
Hold down
Command+Option+R
KEEP HOLDING THEM DOWN, DON'T LET GO as you press the power on button.

KEEP HOLDING THOSE KEYS DOWN.
(all shouting intentional)

Next, you should see either
a. a request to enter your wifi password
or
b. notice that the internet utilities are loading (and the spinning globe).
(NOW let the keys go...)

The internet utilities take a while to load, be patient.

Can you just TRY this and see if you can get this far?

Do this and get back to us.
Getting the internet utilities loaded is an essential step to moving forward at this point.

 

[Raincoaster]

Yes, I can get into Internet Recovery. It's loading now. Still waiting for the new drive to be delivered!

Internet Recovery loaded and I have four options: Restore from Time Machine, Reinstall macOS Ventura, Safari, and Disk Utility. How should I proceed? I also have the new Corsair X9 drive in hand (literally just arrived!).

 

[Fishrrman]

"Internet Recovery loaded and I have four options: Restore from Time Machine, Reinstall macOS Ventura, Safari, and Disk Utility. How should I proceed? I also have the new Corsair X9 drive in hand "

That's a BIG STEP forward.

OK, here's what to do:

First, get back into internet recovery if you're not there already.

After the internet utilities screen appears, connect the new SSD.

Now, open disk utility.
VERY IMPORTANT STEP:
Go to the "view" menu and choose "show all devices".

Now, look at "the list on the left".
You should see the X9 drive.
Click on it ONE time to select it.
Then... click the "erase" button.

Erase it to APFS, GUID partition format.
When the erase is done, quit disk utility and open the OS installer.

Start clicking through.
IMPORTANT:
When the installer asks WHERE to install, select the X9 and continue.

The iMac should reboot several times.
The screen will probably go dark for a minute or more with no other indication of activity.
Just be patient.

When done, you should now be booted up from the SSD, and you'll see the initial setup screen (choose your language).
At this point, connect the drive that has the CCC backup on it.
(if you have a time machine backup that is more recent, use that, but if no difference, I recommend the cloned backup first).

Setup assistant will ask if you wish to migrate from another drive.
YES, you do, so "point the way" for SA to find the backup and give it time to "digest" things.

Setup assistant will present you with a list of stuff to migrate.
I'd suggest you just migrate everything and let SA go to work.

When done, you should see the login screen, so log in and "look around".

Good luck and let us know how it goes.

One last thing:
Be sure to check the startup disk settings pane, and set the SSD to be the boot drive.

 

[Raincoaster]

Thank you! A couple of questions:

1) When I erase the drive, do I select the parent option of "Micron CT4000X9PRO" or the child option of "X9 PRO"?

I decided to choose the X9 Pro drive and it all seemed to work fine.

2) The formatting options I have are APFS, APFS (Encrypted), APFS (Case-sensitive), APFS (Case-sensitive, Encrypted), Mac OS Extended (Journaled), MacOS Extended (Case-sensitive, Journaled), ExFAT, and MS-DOS (FAT). Of the APFS options, do I chose the regular option as there is no GUID partition format?

Here I just chose APFS and got the GUID option by default, at least that's what shows up in Disk Utility. Installing OS Ventura to the new drive now!

Edit: A further update. It appears that on the reboot, the system is attempting to boot from the old broken drive instead of from the new external drive. Is there the MacOS equivalent of BIOS settings that allow me to change the boot order?

Edit 2: I found that by holding the Option Key I could get into boot options and select the right drive to continue the install. It's now doing its thing installing seemingly uninterrupted now!

Edit 3: It stalled again, attempting to boot the broken drive. Any way to fix this permanently during the reinstall? I can find a way to do it from inside macOS but nothing external.

 

[Fishrrman]

Rain --

Have you thought about ERASING the internal fusion drive (for now)?
Assuming that it's backed up, and you will lose no data, or a minimum amount of data?

That might cause the Mac to "ignore" the fusion drive when booting.

Whether you try this or not is up to you.
You would want to boot (again) to INTERNET recovery, open disk utility, select the internal fusion drive and erase it, leaving it "empty" for the time being.

OK, here's another trick I just learned about a few days' back from another well-informed member here:

You can use terminal to run a command that will ALWAYS invoke the startup manager at boot -- automatically, with no holding down the option key.

Once more, boot to INTERNET recovery.
Open terminal and enter:
sudo nvram manufacturing-enter-picker=true
hit return and enter your password (you won't see it as you type).

IMPORTANT:
Better write down that command on paper, you may not be able to "copy and paste" booted to internet recovery.
There are single space characters between "sudo nvram" and "nvram manufacturing"

If you want to "go back to normal" at some point, again open terminal and enter:
sudo nvram -c

I'm thinking this may "cure" the part about trying to boot to the [not working] fusion drive...

 

[Raincoaster]

Hi Fisherrman,

Thanks very much for all your help. I was able to reboot sufficiently to get the reinstall completed and then get the system restored from the CCC backup. Everything is more or less back to where it's supposed to be!

There are a few minor glitches to work through (BackBlaze software is completely borked, no idea why) and the startup issue remains (I haven't tried your suggestions yet but will later today), despite having the correct drive selected in Settings -> General -> Startup Disk. The Terminal command looks like a helpful workaround if I can't get the macOS setting for Startup Disk to take.

Will post here again with follow-up questions (will have some about figuring out how best to configure the backup drives) but in the meantime, your suggestions have got my old iMac up and running again and it definitely feels snappier than the old internal drive! You were absolutely right!