Conceptually, it’s no different from older Macs. With them, the “BootROM” firmware wasn’t on an actual ROM chip, but was on a flash memory chip, separate from the HDD/SSD holding macOS and your files. And macOS updates occasionally updated that firmware.
If that firmware got trashed for some reason, the result was very similar. No booting until you can somehow re-flash it with working code. And if the chip physically failed, no re-flashing it until you can replace the chip (requires microsoldering) or replace the motherboard.
T2-based Intel Macs also had firmware in the T2 chip. If it would get corrupted, also no booting until you can somehow re-flash it. And if that chip died, then replacement (assuming you could get a replacement chip) would invalidate the content of your internal SSD, because it holds the encryption key.
Those failures were few and far between, but they occasionally happened. Although the low-level mechanisms are completely different from Apple Silicon, the effect, as far as ordinary users are concerned, is really not all that different.
It occurred to me just how crazy expensive those preconfigured OWC Express drives actually are. If you do want TB4-interfaced flash, chances are you’re much better off getting their empty case and installing flash you buy from another reputable manufacturer. For example, while their empty TB4 case is $79, they charge another $391 extra if you want that case equipped with 1 TB of flash. Now even if that were incredibly good flash, consider that if instead you got the really great Samsung 990 PRO, for those same $391 you would be able to afford 2 TB instead of the 1 TB OWC is selling you.
Yeah. That’s why I’ve never bought one, despite their reputation for good quality.
You’re paying for their service and support, and that may be important for a customer that doesn’t know thing-one about computers, but that’s not likely to be the case for us, here.
So… a bootable external drive needs to be created before you experience problems with that computer:
This involves downloading the upgrade installer file but not opening it straight away. The default method (instant install) deletes the installer after the upgrade so it is no longer available for creating an external bootable drive.
About a year ago, I followed your advice and bought two SSK enclosures and two Samsung 990 EVO Plus SSDs from Amazon and assembled them. It was a bunch cheaper than the Samsung T5 and T7 SSDs that I had purchased in the past. (Thank you.) However, I have noticed that the SSK enclosures are quite warm, even hot, to the touch after not much usage, while the Samsung drives stay cool. What is the likely reason? Is this an issue long-term? Is this relevant to the current discussion?
The Samsung T7 got quite warm on a recent backup. But I’ve only used it once so I’m not sure that’s statistically relevant. The older T5s I have didn’t seem to warm up quite as much.
I agree with everything you say but raised my eyebrows at the above. Where can I get a Thunderbolt enclosure for only $35 ($15 more than the $20 USB3 one). I am in UK and always had to pay £80-£100 for Thunderbolt NVMe enclosures. Though I did just see a UGreen one for £65 which wasn’t around at the time. Only $15 more for Thunderbolt would be a no brainer!
Yeah, it wouldn’t really make a whole lot of sense to spend $391 on a Samsung 990 PRO just for backing up. That’s great flash no doubt at all, but most of its performance will be wasted on just backing up. IMHO there is a good argument to be made for a more expensive TB4 case over USB3 even for just plain old backup. But the flash you buy for backup needs to be primarily reliable (and perhaps inexpensive so you don’t skimp on capacity), but performance is really not usually the main concern.
Heat is primarily a function of how much is crunching on that flash. This is also the reason why modern flash often runs considerably hotter than flash from 5+ years ago (see @rbononno’s comment just above with the newer drive getting hotter than the older) — we’re just getting far more iops from modern flash (not to mention usually just outright more cells and more cell density due to nowadays higher capacities) and that comes with increased dissipated power that has to go somewhere (heat).
Even if you are not writing or reading to/from that flash, it can still be doing a lot of work. There’s TM for one or Spotlight index building, but there’s also the flash doing its own housekeeping (eg. re-arranging how/where bits are stored, trimming, etc.). Some cases have indicators whose flashing give you an indication that the drive is doing work. There’s also Activity Monitor > Disk to give an idea at least for the stuff initiated by macOS (not necessarily the flash’s own housekeeping). This used to be easier to keep track of with HDDs because their noise would usually give away what they were doing (spinning up, moving heads, etc.).
A flash enclosure can get quite warm, even to the point where it’s not comfortable to touch. But it should never get scortching hot so it actually presents a fire danger. In a sense, you do want the enclosure to get hot because that’s an indication the heat from the flash chips is actually making it to the body which usually acts as a heat sink (thus good enclosures are often solid Al instead of cheap plastic) to dissipate all this power. Good enclosures will always come with thermally conducting strips that get stuck to both the flash itself and the case/heatsink to ensure good thermal transport. If all of that is done right, then for a given power emitted from the flash, the temperature of your enclosure then just becomes a function of the ambient air temp and flow. In hotter environments is usually where people notice hottest cases. You can of course point a blower at the case to help dissipate, but that’s usually a bit superfluous. Modern flash can indeed usually bottleneck its peak performance when it gets too hot, but it’s rather rare to actually observe that in the wild for more than just very brief periods, much less so with a drive that just backs up. This is also the reason that experience with enclosures that come with internal fans is often mixed. You have to put up with the noise all the time (ironically part of just what we left HDDs behind for), but it’s very rare the added dissipation actually leads to a sustained and measurable performance improvement. Again, as always, this applies to backup and conventional use. High-end flash that sees constant and huge throughput with lots of iops will need to be properly cooled. We have such assemblies in the lab where we collect real-time data at very high rates and need to move it off the flash quickly and in random patterns. But that is vastly different from the type of use most consumers expose their flash to, especially when it’s for backup.
An actually overheating case is most often a sign of poor environment (enclosure in poorly vented area or sitting in between other hot electronics, or having low-conductivity material pushed up against it like a tablecloth) or just poor thermal conductivity. The good news is that this problem can be easily fixed. There are sticky thermal pads of various thickness being sold for cheap ($3 example). You can stick such pads between your case (heatsink) and your flash such that once all screws are firmly tightened there is a real good and tight fit so heat once again easily finds its way again from flash chip to ambient air.
One of the reasons for the cost of that OWC case is both the structural integrity of the case and the fact that the case itself is designed as a large heatsink. At least that’s the implied reason.
Perhaps in the UK things are different, I honestly have no clue about the market over there.
This here is a $40 TB4/USB4 case we have purchased several times. Works well, no fuss.
And here is a $31 TB4/USB4 case — the cheapest I have seen so far. Full disclosure: I have never used it myself, but I know one of our postdocs bought it for their personal setup and at least so far I haven’t heard any complaints.
The UGreen you mention is about $70 here. I like its fins, but honestly, I think for that kind of money though I’d be tempted to instead just get the $79 OWC because it’s a very nicely engineered case and a known quality product from a serious company.
On a related note, I often deal with a lot of different flash sticks that I quickly need to access before stowing them again (think rotating backups and data archival). I recently got myself this TB4/USB4 dock. It doesn’t protect the flash stick like a proper case (so it’s not a permanent solution by any means), but it’s great for quickly mounting and unmounting and swapping between lots of NVMe sticks. It’s also just $40. I used to have USB3 docks like this, but at such a small cost difference, IMHO why even bother with anything less than TB4/USB4?
The Inatek one does not ship to UK but the Maiwo one is available here for £42, and I also found this Mokin one slightly cheaper at £40 and it has better reviews.
There has obviously been a quiet revolution on this since I last bought one. I am mulling getting the Mokin to replace my only USB3 one.
The dock is also very interesting but doesn’t really fit my usage.
Thanks yes I had noted that. I am in two minds about it. My large (4TB) Thunderbolt NVMe drives do get hot when being loaded with hundreds of GB at a time so a built in fan might be good. OTOH I don’t want to be able to hear it. Currently I point a small fan at them when loading data (not very often) but not in normal use.
I’ve seen external enclosures of other kinds also get hot. But it’s probably not going to be a problem. SSDs do tend to run hot when not idle, but they’re designed for that. If doesn’t get so hot that it thermal-throttles (you’d see that as a massive drop in performance), it should be fine.
As for why? Make sure you installed the thermal pad correctly when assembling the SSD. Remove the clear adhesive backing from both sides of the pad, so it will have good contact with both the SSD and the enclosure’s heat-sink surface.
Assuming that the pad is good, the T7 may have a thermal solution that dissipates heat more easily than the SSK’s enclosure. Also, the 990 EVO+ may generate more heat than whatever’s inside the T7 - this is likely, since it’s probably a higher-performance device and may be providing more throughput than the T7.
Any non-junk SSD will have its own thermal-monitoring systems. If the chips get too hot, the on-board controller chip will throttle performance, to prevent damage. You’ll see it as greatly reduced performance, but it shouldn’t suffer any damage.
If this happens, or if you are concerned that it might happen (e.g., due to the ambient temperatures where you’re using it), you can get enclosures with fans. That will definitely keep the chips cooler, at the expense of a bit of noise and a slightly higher cost.
Ugh! Fans! How did I ever put up with them over all those decades!?
The other thing you can do if the heat concerns you is to put the SSD on a heat-conductive surface rather than the wood or covering on your desk. An old brass plate, a tin candy box, or the like. It won’t be a fan but it will (sometimes surprisingly) drop the temperature.
These days, when someone hears “fan” they immediately think of things like the old “Wind Tunnel” PowerMacs. But this is not the same thing.
The fans typically found in single-drive HDD/SSD enclosures (not multi-drive NAS systems) are pretty small and often have speeds controlled by device temperature. Depending on the design of the rest of the enclosure and where it is physically situated, they may make very little noise. If you have other equipment with fans in the room, you may not hear a thing over the pre-existing sound.
Having spent too much time in server rooms with Xserves, RAIDs, and other such acoustic monstrosities I’m now extremely sensitive to 60-cycle noise, even relatively quiet spinning metal drives. SSDs and astonishingly quiet MacMinis & Studios are a god send and ever so speedy as well.
I’ll take your word on the SSD fans. It seems entirely reasonable that they have been able to engineer this.
It’s not so warm that it’s uncomfortable, and certainly no scorching hot; It was just surprisingly warm compared to the Samsung SSDs.
(@Simon also mentioned this.) I did not install the thermal pad at all. The “stick” barely fit in the enclosure without it; the chips were rubbing on the side of the enclosure and the other side of the stick was closer than half the thickness of the thermal pad. (I trimmed a small part of the thermal pad and applied it, and the enclosure sheared it off.) Maybe I was doing it wrong, but I don’t see how. There simply wasn’t clearance.
I have not noticed any slow down, but I really don’t do anything intensive for a long time.
More by happenstance than by design, the SSD when in use is supported at both ends with air all around its middle 80%.
