External Bootable SSD Late 2015 iMac

[FriedApples]

I wonder if it’s an issue with NVMe drivers. The computers boot rom needs to be up to date to use external NVMe drives. I think you have to install Catalina (or maybe high Sierra works as well - not sure on that) on that machine from a non-NVMe drive first. This will update the boot ROM. After that you should be able to use external NVMe drives. My wife uses a 2016 16” touchbar MBP with Sierra and it does not recognize the external NVMe SSD because it has not had the boot ROM updated. Also note that the HP dock shows unsupported for me as well but appears to work anyways.

I have a positive update on this. Shortly after I had major problems with the enclosure, I decided to start the RMA process for the OWC enclosure and along with it sent one of the ADATA SSDs that appeared dead. About a week or so later, I received both components. The serial number of the returned enclosure matched the one I sent for RMA. Nothing changed with macOS on either of my Macs during this time. Both previously inoperable ADATA SSDs were immediately recognized by macOS under all configurations I mentioned in a previous post. I have been using both ADATA SSDs and the Inland SSD without issue through both the HP and Caldigit docks for the past 1.5 months. Additionally, the SSDs no longer get ridiculously hot under load. I now recommend this setup with reservations -- if users of the enclosures experience issues they should contact the helpful support team at OWC.

 

[honeycombz]

Hi, could someone clarify some things for me here. I have the late 2015 iMac 5k with the junk hdd in it. I was going to get an $11 Sabrent UASP USB enclosure with a PNY or Crucial 1tb SSD and keep this to under $100 since this is an aging machine but should I be getting a setup more like the owc envoy express thunderbolt enclosure (https://eshop.macsales.com/item/OWC/TB3ENVXP00/) and the 1tb owc aura p12 pro nvme2 chip thing? (https://eshop.macsales.com/item/OWC/S3DN3P2T10/). Will this setup work and be bootable and be that much better than the cheaper UASP option? Don’t know much about this but way too lazy to open the machine up to replace the internal right now.

 

[Brian33]

The OWC Envoy Express enclosure you link above is a Thunderbolt 3 device; your iMac (and mine) have Thunderbolt 2 ports. You can use a TB3 device with your mac, but you'd need Apple's TB3-to-TB2 adapter (here)

As a bidirectional adapter, it can also connect new Thunderbolt 3 devices to a Mac with a Thunderbolt or Thunderbolt 2 port and macOS Sierra or later.

It's $49, so that's in addition to the higher costs of the OWC parts.

In my humble opinion your cheaper plan would probably be good enough, even though I think our computers are limited to 5 Gbps USB 3.0 ports. I haven't actually booted that way, though, so I'm not sure what the performance would be.

Anyone out there booting an SSD off one of these slower USB 3.0 ports?

 

[honeycombz]

Yea. I would prefer to keep it simple but would also like trim enabled. Do these USAP enclosures all support trim? It looks like some of the NVMe ones do and maybe there is a startech enclosure that does.

 

[Brian33]

Good point about Trim. I've seen somewhere that Trim support will only work with a Thunderbolt connection, and not with a USB connection, but I'm not sure whether that's true. You should research that some more.

I can say that Trim does work over Thunderbolt 2 with a SATA SSD, on a Late 2015 iMac, as I have verified mine in System Report.

 

[honeycombz]

How are you connecting a sata ssd to thunderbolt 2? It looks like the cable adapter you linked to woukdn’t work as this machine has no usb c ports? There is also this thunderbolt enclosure that another poster used https://www.synchrotech.com/product...sd-drive-external-enclosure-delock-42510.html which seems good but it is not bus powered (are any thunderbolt enclosures?) and I wonder if that would be a hassle to have to power it on and off separately? Can you option boot into a thunderbolt drive? Also, it looks like Crucial SSDs have active garbage collection which could be a decent compromise without trim support if going the USB route?

 

[Brian33]

How are you connecting a sata ssd to thunderbolt 2?

I have three Thunderbolt enclosures, daisy-chained off my Late 2015 iMac. I have two AKiTiO Thunder2 Duo Pros (Thunderbolt 2), and they have been fantastic! The other is an older AKiTio Neutrino Thunder D3 (Thunderbolt 1), which works perfectly but the fan is more annoying. Contents are four HDDs and two SATA SSDs.

It looks like the cable adapter you linked to woukdn’t work as this machine has no usb c ports?

The Thunderbolt-3 end of the adapter (looks like USB-c connector) would plug into a Thunderbolt-3 enclosure. At the other end of the adapter you plug in a Thunderbot-2 cable (looks like a DisplayPort connecter) and plug the other end of the cable into the 2015 iMac.

I haven't actually used that adapter, but it is supposed to work this way. (Also can be used to connect old TB2 device to a new TB3 computer -- thus the "bidirectional" claim.)

There is also this thunderbolt enclosure that another poster used https://www.synchrotech.com/product...sd-drive-external-enclosure-delock-42510.html which seems good but it is not bus powered (are any thunderbolt enclosures?) and I wonder if that would be a hassle to have to power it on and off separately?

That looks like it would work for you. It appears to be Thunderbolt 1 only, though (specs say "10 Gbps Bi-Directional Throughput"), so half as fast as TB2. It's getting tough to find TB1 or TB2 enclosures these days, and they still seem a bit pricey. I got two of mine on eBay.

There are bus-powered TB3 enclosures available. I personally don't think the power issue is a big deal for a desktop -- you could keep the enclosure powered on all the time, even when the iMac is off, so no extra hassle. I do that with my external enclosures.

EDIT: a bus-powered enclosure will NOT work with the TB3<-->TB2 adapter, because the adapter itself doesn't pass the power on to the device

Can you option boot into a thunderbolt drive?

Yes, no problem -- I've done it.

Also, it looks like Crucial SSDs have active garbage collection which could be a decent compromise without trim support if going the USB route?

I believe most, if not all, SSDs have active garbage collection and I'd expect them to work ok even without trim -- certainly better than a rotating hard drive. But I don't have personal experience with going without Trim.

 

[honeycombz]

After thinking about it I think I’d like to focus on just getting a thunderbolt 2 enclosure or the thunderbolt 3 w/dongle solution that doesn’t break the bank if possible. Not seeing that Akitio one available. Anyone know of another brand that I might be able to target? Would it be better to get one of these bus powered NVMe SSD enclosures? https://www.amazon.com/OWC-Envoy-Ex...derbolt+3+ssd+enclosure&qid=1663174485&sr=8-3

I get the impression that maybe those chips overheat easier?

There is also this one which takes 2 but would rather a traditional ssd enclosure.

Thunderbolt 3 To Dual NVMe M.2 SSD Tool-Free Enclosure

FALSE

sabrent.com

And that Synchrotech brand does have a Thunderbolt 3 / USB C drive for a decent price. Wondering if it is true T3 thiugh or just able to connect via the port. Anyone know anything about this brand? https://www.synchrotech.com/product...-drive-enclosures-usb-c-thunderbolt-3_01.html

 

[Brian33]

TB2 devices will be hard to find and probably not worth the price in the long run (unless you find one super cheap). TB3+adapter seems better to me -- when you someday get a new computer, you'll get the benefit of TB3 connection speeds. And, I'd get an NVMe case, not SATA.

Would it be better to get one of these bus powered NVMe SSD enclosures?

To reiterate, a bus-powered TB enclosure will not work with the adapter, as the adapter doesn't pass through the power. So if you go with Thunderbolt, you'll have to get one with its own power supply.

Another note: the Apple TB2/TB3 adapter is the only one I know of that is advertised as "bidirectional". I don't recommend buying some cheaper brand adapter for this usage scenario.

There is also this one ehich takes 2 but would rather a traditional ssd enclosure.

Thunderbolt 3 To Dual NVMe M.2 SSD Tool-Free Enclosure

FALSE

sabrent.com

As far as I know, that would be a fine choice. I think there are not many TB3 enclosures out there that have their own power supply.

There is a giant thread about these enclosures -- there might be a few mentions of powered ones:
https://forums.macrumors.com/threads/thunderbolt-3-m-2-nvme-ssd-enclosures.2027925/