Late-2015 iMac 27" can't see Crucial X6 2TB drive

Question

Late-2015 iMac 27" can't see Crucial X6 2TB drive

I have a late-2015 iMac 27" with a wonky fusion drive and want to attach an SSD and boot off that. I bought a Crucial X6 2TB drive(has USB-C to USB-C AND a USB-C to USB-A adapter). I plugged it into Monterey on the iMac, but it doesn't recognize it. Nothing is coming up in Disk Utility. Rebooted, still nothing visible. I took it to my 2019 MacBook Pro and it could see it using the USB-C to USB-A adapter. So I erased the ex-FAT partition and set it to APFS and took it to the iMac. Still doesn't recognize it. Tried multiple USB 3 ports. Nothing. Anyone have any ideas why? The drive is good, the cable is good. I just can't see it on a newly installed Monterey OS on the late-2015...any ideas would be greatly appreciated.

Posted on Oct 15, 2023 12:30 AM

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Answer 1

dialabrain

Level 10

135,431 points

Oct 15, 2023 1:24 AM in response to JohnJohnsonIII

Nothing comes to mind other than the adapter is not tight or fully plugged into the USB A ports. If you select "System Information" by holding the option key while selecting the Apple menu, does the drive show when you select USB from the list?

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Answer 2

Oct 15, 2023 3:19 AM in response to dialabrain

For my iMac:

Desktop computer

If your Mac isn't a laptop computer, follow these steps:

Shut down your Mac, then unplug the power cord.
Wait 15 seconds, then plug the power cord back in.
Wait 5 seconds, then press the power button to turn on your Mac.

I did as instructed, but sadly, no luck. It just doesn't show up in Disk Utility or Finder.

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Answer 3

dialabrain

Level 10

135,431 points

Oct 15, 2023 2:33 AM in response to JohnJohnsonIII

It should show up in Monterey.

Try… Reset the SMC of your Mac - Apple Support

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Answer 4

Jack-19

Level 8

46,182 points

Oct 15, 2023 1:45 PM in response to JohnJohnsonIII

The Crucial X8 is the "upgraded" version of the X6 and has improved speed, reliability, and endurance. It might be worth a try if you want to stay with Crucial.

Otherwise, the LaCie Mobile SSD Secure USB-C Drive - Gray - Apple has been very dependable for me. However, unlike the Crucial X6 SE, it doesn't include a USB-A adapter in the box, so with the LaCie, you'd need an adapter or cable, such as the Belkin 3.1 USB-A to USB-C Cable.

Some modern external drives, including the above LaCie, do have the hardware encryption feature, however, it doesn't have to be used, and I often recommend that you don't. Most drives require an additional application to use the hardware encryption feature, so it can be left ignored.

-Jack

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Answer 5

dialabrain

Level 10

135,431 points

Oct 15, 2023 3:51 AM in response to JohnJohnsonIII

Sorry to hear. FWIW, I have a Late 2015 5K iMac running Monterey 12.7 and I have SSDs from WD, Sandisk & Crucial and they all mount. Maybe someone will have another idea.

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Answer 6

Oct 15, 2023 2:30 AM in response to dialabrain

Wow--it actually DOES show up on the USB list. But why am I not able to see it in the system...It doesn't show up in finder even though preferences includes external disks. Can't see it in Disk Utility even though I have it set to show all disks...

Looking at it on my MBP in Disk Utility I see the following:

And if I click on the Container I get the following:

And finally clicking on the newOS I get:

But strange it will not show on Monterey but will on Ventura. I checked and supposedly Monterey reads APFS and all accounts say to use GUID partition map for the SSD...any ideas?

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Answer 7

Oct 15, 2023 12:12 PM in response to dialabrain

I came across another thread describing my problem:

SSD not seen in Disk Utility but shows it… - Apple Community

I followed some links and saw a LOT of people having external SSD issues with Monterey. I have 12.7 and the Crucial X6 is not coming up. I don't know if the SE in the product name means "Slightly Eccentric", but that could be. Can you tell me the different product models of WD and Sandisk that you have used for booting your late 2015 iMac? I may head down to BestBuy(all we have here in Hawaii) and buy one. Thanks in advance!

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Answer 8

Oct 15, 2023 12:28 PM in response to dialabrain

Excellent, I see a similar one at Costco that I can get today. The only thing I worry is that it has hardware encryption and I hear that hardware encryption can be a problem when using for boot drives, no?

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Answer 9

Oct 15, 2023 1:25 PM in response to dialabrain

The Sandisk is here:

https://www.costco.com/sandisk-1tb-extreme-go-ssd.product.4000175415.html

They also have a Samsung T7:

https://www.costco.com/samsung-2tb-portable-ssd-t7-touch.product.4000059709.html

BestBuy has the Crucial x8 2TB below:

https://www.bestbuy.com/site/searchpage.jsp?st=crucial+x8+4tb&_dyncharset=UTF-8&_dynSessConf=&id=pcat17071&type=page&sc=Global&cp=1&nrp=&sp=&qp=&list=n&af=true&iht=y&usc=All+Categories&ks=960&keys=keys

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Answer 10

dialabrain

Level 10

135,431 points

Oct 15, 2023 1:32 PM in response to JohnJohnsonIII

Sorry. Not familiar with any of them. Even the Crucial drive, although apparently the same model as mine, has a different case and I don't know what other changes it may have. "Hardware Encryption" makes me nervous.

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Answer 11

ku4hx

Level 7

23,688 points

Oct 15, 2023 1:38 PM in response to JohnJohnsonIII

We have five Macs; at one time all were on Monterey.

Each iMac (3) has three external SSDs; two MBPs (2016 & 2020) have either one to two SSDs each when used non portable.

We never had a problem with any external drive on any Monterey machine. The drive are all Samsung T7 models; various other drives we use for data transfer when needed (PNY 250GB portable SSD mostly) have likewise never had a problem.

The three iMacs are now on Sonoma with the same SSD setups and the same no problem condition.

I'm so thankful to not be a part of the "LOT" of people having this issue.

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Answer 12

Oct 21, 2023 3:47 PM in response to dialabrain

Turns out the problem was that I was formatting for APFS when, because it was Monterey or earlier, it could not read APFS, but Mac OS Extended(Journaled). So after reformatting, all the drives worked. I ultimately used the cheaper X6 which can do USB 3.1, which is higher than the native 3.0 on late-2015 iMac. A blackmagic test shows about 416MB/sec when running. The problem is that the boot takes forever. But once running, all seems gold. Another oddity is that SOME dmg files, when run, do nothing apparent. I have to go to Terminal and use "hdiutil attach xxx.dmg" and it will run. Some DMG files work, some don't. Logitech files did, Chrome did not. Adobe's creative cloud installed did not. Eventually those had to be done via terminal. But all is good save for the slow boot time of several minutes.

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