I use external Samsung T5 disks to test deployment of new os and software. Had the same problem as you. Here is what fixed it.
Install a wired keyboard that works for NVRAM resets, not all work, press CMD-Option-P-R and keep pressed until you hear the 5th chime - you need to reset the NVRAM at least four times consecutively.
I took a look at the apple.com thread and there are conflicting answers there about booting from a bus powered drive but since it boots my MBP and shows up in option boot apparently thatās not really the issue. I will dig up another cable and try as wellā¦and had thought about the PRAM reset but had not tried that yet.
Iāve been using a USB keyboard and mouse through most of this troubleshooting since Screens wonāt really work for things like option or command R bootā¦Iāll try the cable first (I think I have another USB C to A that came with my other T7 drives) and then the PRAM reset to see if that helpsā¦will report back with success/failure/request for more ideas.
Laterā¦
Nopeā¦neither worked. I can still select the T7 in Startup Disk or via option boot with reset and different cable but it boots to the internal regardlessā¦so I might be tilting at windmills here.
Yes, I also noted sometimes a T7 boots and yours does not boot a 2014 MacMini.
Iām having the same MacMini so Iām very interested in your results.
To explain my earlier answer in this thread: The Samsung User manual for those SSDās rate the T5 as ā5 Volts, 0.8 Ampereā, and the T7 as ā5 Volts, 1.5 Ampereā. The 5 Volt is logical (USB standard), but the T7 power draw is potentially larger than the T5s.
BTW, some strange things: The ratings are only mentioned in the Korean section of the user manual, probably because only the Korean law requires this. And the T7 user manual is not on the Samsung.com USA website, I found it on the site of my European hardware supplier.
As my mini is maxed out on all USB slots Iāve expanded the USB slots using a USB hub with itās own power brick. If you have one you could try if it helps booting from the T7.
The USB 2.0 spec allows up to 0.5A for a high-power device. USB 3.0 allows up to 0.9A. USB-C allows up to 1.5A. Any additional power requires implementation of either the battery charging spec (which, I believe, canāt be used simultaneously with moving data) or the power delivery spec over USB-C.
In other words, the T5 may be able to draw the power it requires from a USB 3 port (0.8A is less than 0.9A), but the T7 may not be able to get what it needs unless it is plugged in to a USB-C port.
A 2014 Mac mini doesnāt have any USB-C ports, so there may be problems if the driver requires more than 0.9A of current.
The strange thing is that the drive seems to work OK as long as youāre not booting it. The only explanation I can think of is that Appleās USB-A ports have a proprietary high-power mode (used for the SuperDrive), which might also be able to power the T7. But that power mode may not be available before macOS starts running.
But the fact that the drive appears as a boot device when you hold down option, seems to indicate that this isnāt the case either.
Itās definitely worth trying a powered hub, if you have one. My Mac (2018 mini) has an Anker 10-port hub which is used for many devices, including my backup drives. I can boot from these drives, but that doesnāt mean anything because these drives have their own AC power supplies.
If the drive shows up properly in the boot loader, the drive is getting enough power. Or rather I should say, if it can show up its volume in the boot loader, the power itās receiving is sufficient for the Mac to continue to boot from it.
I would be very interested in hearing what the PRAM reset does.
I doā¦but itās in use on my iMacā¦ ut I think I will /or tow it long enough to see if the power draw is the problemā¦if it is and the performance increase is worth it I can spring for another one. Orā¦since itās file server performance is fine and itās only the remote management slowness I might blow it off as not worth itā¦but y least I would know the answer then.
Nothingā¦as did the cable swap. I did notice that on some option boots the T7 shows up in option boot with the volume name and sometimes it shows up as efi_bootā¦and that didnāt start until after the PRAM resets.
I had edited my precious post to say that on the Discourse page but wasnāt sure if the edits would get sent to the listā¦apparently it didnāt.
AFAIK the boot process is very energy intensive. Both for the computer and the bootdrive/SSD. Massive reads/writes and checking of correctness. And in my experience the boot process falls back onto booting from the internal drive if anything on the chosen bootdrive fails any of the tests. A low power situation will probably result in switching to the internal drive for booting. That the T7 shows up as a bootable drive is logical, it gets only read and checked if there is a valid system on the disk. Reading is not very energy intensive. Too bad the docs from Samsung donāt state the needed energy for reading, writing and booting from their SSDs.
Itās definitely worth trying a powered hub
Given the specs Shamino has given make that a powered USB-C hub. I have only a powered USB3 hub and doubt if a T7 gets enough juice from that.
When you select the T7 in the boot loader, does it start to boot from it and then after a while fall back to the internal, or does it start booting from the internal right away?
Also, if the working theory is just that the T7 is exceeding the peak power draw of USB-A on the Mac mini, do you have a powered USB-C hub you could play with? Would be interesting to hook up the T7 to it (via A-C dongle if you donāt have a C cable) and see it that changes anything. A proper C port on a powered hub should be able to deliver 15 W which is 3 Amps at A voltage levels, so more than enough to power the T7.
Can you connect a USB-C hub to a Mac without USB-C ports? A 2014 mini has type-A ports and TB2.
Still, I would find it surprising if a USB-A port canāt power the device at all. Samsungās product page says (if you scroll down to the Multi-device compatibility section) that āT7 is compatible with USB 3.0 and USB 2.0ā. Which tells me that even a USB 2.0 port should be able to supply enough power.
Unfortunately, it may simply be that the T7 isnāt bootable on this Mac. We know that, for instance many WD MyPassport drives canāt boot Catalina. Maybe it is due to power issues. Maybe something else. Itās hard to tell without diagnostic tools that are probably not available outside of Samsungās own labs.
Those MyPassport drives have hardware disk encryption and those drives canāt be used in another case if the USB board goes bad so itās not surprising they have issues booting as well.
Since I have a Samsung 500gb T7 not being utilized at the moment, I decided to clone my main Catalina startup volume to it to see if it would boot like the T5 models do without issue. I have a 2012 Mac Mini 2.3 GHz i7 Quad Core. It boots fine from the T7 directly connected to the computer port and also from a USB 3 hub (Insignia). So for me, no power issues here. I am selecting the boot disk from the Startup Disk preferences pane.
Now, I know the OP was trying to boot Monterey which I canāt do since Catalina is as far as I can go with a 2012 Mini but at least with my computer, there are no issues booting from a T7 (or a T5).
It seems like thee is a delay and the drive light flashes off and on showing accessā¦and the logo and progress bar appear normal sized for 15 or 20 secondsā¦then after a bit the logo and progress bar blink off and back on larger (like it appears on a smaller monitor) followed by about 3 or 4 seconds of progress bar and then the users on the login page appear.
I have one thing you can try if everything else fails. This is how I do it when working with deployment testing.
Boot up with internal.
In Disk Utility, Format the disk with MS DOS FAT
Quit Disk Utility and start it again.
Format the disk with MacOS Extended. (Not APFS)
Start the installer from /Applications on internal disk.
Choose āShow All Disksā¦ā Choose the external disk.
The installer will now format the external disk to APFS and make sure it has the right boot disk layout, which in the past has made a difference several times for me. There might also be some other apple magic going on. Tested this just now with Samsung T5 and Mac mini late 2014. This is with Monterey 12.2 which came yesterday.
Thanks for testing, good to know both situations work.
The T7 comes in three sizes, 500 GB, 1 TB and 2 TB. Probably Samsung leaves all other components the same on all three models and adds only extra memory. Most likely extra memory chips require more power.
I read this thread back to see if Neil mentioned the size of the T7, but found nothing. But as he uses it to backup multiple MacBooks itās likely larger than 500 GB.
What also is a possibility to get info on the power needed is going to System Info (About this mac/ System info/Hardware/USB) while the T7 is connected to the mini. (Wording will differ, different language and different System.) It will give a top-down view off the USB hubs and attached disks, including āPower availableā and āPower neededā.
On a sidenote, when I oriented on buying the 2014 mini (back in 2016) Iāve read a number of reviews. One remark I noted said: āThe 2014 mini has 5 USB-ports and the earlier miniās have 4.ā It might be that Apple maxed out the available power to feed the fifth USB port. According to MacTracker the 2012 and the 2014 mini have the same form factor and weigh almost the same. So probably the same power supply.
It still is possible that itās a power problem, but Shaminoās suggestion that the T7 is not bootable is also still valid.
As an alternative option (reading the specs in MacTracker) a Thunderbolt to USB-C connection could be a solution (if the T-bolt port is still unused).
I checked out the power requirements and here is what I found. First, using my Toshiba XS700 240gb as the boot drive plugged directly into the computer:
Ok, I did a little more testing today. The T7 is the 2TB mode and likely takes a bit more power than the smaller ones. My conclusion after my testing is that thereās some strange incompatibility with booting that model drive on at least this particular late 2013 mini. I did see the recommendation to reformat the drive as FAT and then reinstall againā¦and I might end up doing that. Howeverā¦Iāve already copied over the 700 GB of CCC TM clones folders to it so would have to copy them back to a spinning drive and back to the T7 afterwards and Iām tired of mucking with this for today at leastā¦if I get bored I might try that again although I did that alreadyā¦the drive came as FAT and I nuked it to a single GUID/APFS volume before doing anything. Iāve reinstalled Monterey to the T7 3 (or maybe 4, canāt remember) times with both a single APFS container for the boot volume and another APFS container for the shares as well as a single APFS container with just a single partitionā¦so Iām not thinking that will do anything for me unless nuking it back to FAT again causes some changeā¦but when I get bored Iāll try it again.
Hereās the results of my additional testing today.
Booting from the internal drive with the internal drive selected as startup and the T7 attached. About 0:55 with the small logo and progress bar then total of 1:03 with the larger logo/bar to the login screen. No T7 drive light flashing
Booting with the T7 selected as startup. Same indications as before but about 1:26 for the small logo portion and 1:36 total with the larger logo to the login screen. There was very brief intermittent drive activity light on the T7 about 10 and 40 seconds into the first 0:55 with none during the last part to the login screen.
Option boot with the T7 selected then immediately selecting refi_boot and return when that screen appeared. About 0:10 to the option boot selection screen, 1:24 with the small logo and 1:36 to the login screen. No flashing light on the T7 but the light was on.
Shut down my iMac to borrow the powered USB A 3.0 hub, hooked that to the mini and the T7 and keyboard/mouse to the hub. Same dual size logo routine and 1:37 with the small logo and 1:43 to the login screen. This one was slightly different as the screen stayed black for about 30 seconds after the bong then about 2 seconds of T7 drive light activity before the small logo portionā¦but no drive light activity after that.
I also did some more googling and saw several reports that said their 2013 mini was booting just fine from a T7 although the size wasnāt specifiedā¦as well as reports that said it never worked and some that said it worked some of the time but not reliably. Soā¦apparently thereās some weird issue going on at least between this model and the T7 for some peopleā¦and frankly Iāve probably wasted waaaay too much time on it alreadyā¦but after hearing and reading about how it worked for some my stubborn gene kicked in. As I said earlier in the threadā¦the network performance to the T7 from the laptops that CCC backs up to it works fine and about 10x as fast as the Seagate Backup+ drive those shares used to be on so Iām not really losing anything there. Itās just the performance of macOS on boot time, app load time, etc that I would have liked to improveā¦especially as the internal spinning drive is now 8+ years oldā¦but other than mucking around with it this week I only use Screens to remote in and manage the thing maybe once a month or whenever CCC tells me the job failed and in the past that was usually because the Seagate drive dismounted itself. I solved that issue by setting up both Keep It Spinning on the mini as well as a CCC job on the mini which copied a small text file from the internal drive to the Seagate once a dayā¦not sure which of those actually fixed the dismounting issue since it was 6 or 8 months back when I did it.
If/when I try reformatting the SSD Iāll report back on success or failure but otherwise unless somebody has another idea Iāll just live with it.
Did you check in your system report what values for power are there similar to what I posted before your post? That might give you some idea of what is required. Also, maybe this is a Monterey issue of some kind.
