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chublet

macrumors member
Original poster
Feb 10, 2018
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AS per the title, anyone got any recommendations as to decent external enclosures for a 250GB SSD that I am planning to use on my iMac as a boot drive? I was very surprised to see that the enclosure can have a significant impact on the transfer speeds as I thought it would be simply a SATA and power connection but am I missing something?

As always, any and all advice appreciated!
 
OWC makes a few good enclosures. I use a Thunderbolt2 enclosure with 2 drive slots, one with an 3.5" SSHD boot drive, the second a 7200RPM large drive which is used for external storage.

Speeds <> the enclosure are:
  • Thunderbolt 3 (USB-C type connector) ~40Gbps
  • Thunderbolt 2 (MiniDVI type connector) ~20Gbps
  • Thunderbolt 1 (Mini DVI type connector) ~10Gbps
  • USB 3.1 ~10Gbps
  • USB 3 ~5Gbps
  • Firewire 800 ~800Mbps
  • USB 2 ~480Mbps
  • Firewire 400 ~400Mbps
  • USB 1 ~12Mbps

Check the specs on your Mac to find out what ports it has, then choose the fastest that is compatible with your Mac.

Generally, anything under USB3 is not a good candidate for an external boot drive. SSD\SATA3 drive transfer speeds are ~6Gbps. The additional bandwidth might be useful if you attach other devices in the chain. Thunderbolt can daisy chain displays, or other Thunderbolt devices, so the drive may only use 6Gbps of bandwidth but the rest could be used to drive displays or other things.
 
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I recommend an Oyen Digital MiniPro:
https://www.amazon.com/MiniPro-USB-...20264397&sr=8-2&keywords=oyen+digital+minipro

I bought the older USB3 version and it's built like a tank.

If you're going to use it with a Mac that has USB-a ports, just use a USB-c to USB-a cable. It comes with both.

Costs about $10 more than other enclosures, but then again, it's built like a tank.
I've had several Oyen Digital enclosures -- including a handful of MinPros -- and they have all worked reliably and well.

And I concur about getting one with USB-C. No dongles needed -- just a different cable. And Oyen gives you one, as you say.
 
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OWC makes a few good enclosures. I use a Thunderbolt2 enclosure with 2 drive slots, one with an 3.5" SSHD boot drive, the second a 7200RPM large drive which is used for external storage.

Speeds <> the enclosure are:
  • Thunderbolt 3 (USB-C type connector) ~40Gbps
  • Thunderbolt 2 (MiniDVI type connector) ~20Gbps
  • Thunderbolt 1 (Mini DVI type connector) ~10Gbps
  • USB 3.1 ~10Gbps
  • USB 3 ~5Gbps
  • Firewire 800 ~800Mbps
  • USB 2 ~480Mbps
  • Firewire 400 ~400Mbps
  • USB 1 ~12Mbps

Check the specs on your Mac to find out what ports it has, then choose the fastest that is compatible with your Mac.

Generally, anything under USB3 is not a good candidate for an external boot drive. SSD\SATA3 drive transfer speeds are ~6Gbps. The additional bandwidth might be useful if you attach other devices in the chain. Thunderbolt can daisy chain displays, or other Thunderbolt devices, so the drive may only use 6Gbps of bandwidth but the rest could be used to drive displays or other things.


That is great info, thanks very much! My late 2013 iMac only has USB 3.0 and Thunderbolt 1, it seems pretty much impossible to get a TB1 enclosure for anything less than silly money so looks like a 3.0 one is my only option, should still see a decent increase over my 5400rpm internal drive though!
[doublepost=1520289784][/doublepost]Don't really want to start a new thread in my search for ssd answers so I guess my next question MAY fit alongside this, even if only vaguely...

I have read about TRIM and how it is a good thing for external SSDs, but also that previously it has not been enabled for third-party external SSDs over USB, but is for Thunderbolt (thats how this is relevant in this thread!).

My iMac is a late 2013 21.5", running High Sierra - I intend to use the external SSD as my boot drive and will have all my apps and iTunes installed on it, but the rest of my data etc will all be on other drives, mainly external spinners but also my now-redundant internal 5400rpm drive.

I believe that my SSD will be formatted with APFS, is this correct? If so, does this do the same job as TRIM or do I have to enable that manually, and is that even possible?
 
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That is great info, thanks very much! My late 2013 iMac only has USB 3.0 and Thunderbolt 1, it seems pretty much impossible to get a TB1 enclosure for anything less than silly money so looks like a 3.0 one is my only option, should still see a decent increase over my 5400rpm internal drive though!
[doublepost=1520289784][/doublepost]Don't really want to start a new thread in my search for ssd answers so I guess my next question MAY fit alongside this, even if only vaguely...

I have read about TRIM and how it is a good thing for external SSDs, but also that previously it has not been enabled for third-party external SSDs over USB, but is for Thunderbolt (thats how this is relevant in this thread!).

My iMac is a late 2013 21.5", running High Sierra - I intend to use the external SSD as my boot drive and will have all my apps and iTunes installed on it, but the rest of my data etc will all be on other drives, mainly external spinners but also my now-redundant internal 5400rpm drive.

I believe that my SSD will be formatted with APFS, is this correct? If so, does this do the same job as TRIM or do I have to enable that manually, and is that even possible?

TB2 uses the same connectors as TB1, so that is still an option. APFS is only supported on internal SSD, not external.

SSD will have 6Gbps\600MBps (SATA3) bus speeds (actually less as read\write speeds on SSD tend to top out around 500-550MBps which is roughly 4Gbps. So, USB3 should work just fine, but make sure the enclosure supports boot drives. Not all do, you need to look for UASP (SCSCI over USB) support. Cheap enclosures may not support this. OWC has a good selection of enclosures and is very detailed on their specs as to whether they will support booting from the drive\enclosure. Don't go cheap and deal with frustrations if this is going to be your boot drive!

TRIM may or may not work with a USB drive, but some SSD have their own TRIM type capabilities (garbage collector or other "brand" names). I suspect UASP capable drives should support TRIM, but you have to enable it via commands from Terminal (“sudo trimforce enable”).

To know for sure if a USB connected SSD supports TRIM, go to Apple > About This Mac > System Report > Hardware > SATA/SATA Express > and look for “TRIM Support” under the specs. If TRIM Support is not listed, your enclosure most likely does not support TRIM. If it is listed but says “No”, you should be able to enable it. But, I understand TRiM can be a problem for some SSD so make sure the drive you buy supports it.
 
APFS is only supported on internal SSD, not external.

Thanks for the detailed reply, however are you sure that APFS is only supported on internal SSD as it is supported on my external 7200rpm drive that is connected by USB so why is SSD any different? I converted it to APFS only a couple of days ago using Disk Utility and the System report shows:
disk1s2:

Capacity: 4 TB (4,000,408,625,152 bytes)

BSD Name: disk1s2

Content: Apple_APFS
 
The Delock 42510 Thunderbolt enclosure has served me well now for going on 4 years. I booted my Late 2013 iMac from it for a few years and then loved it so much that I invested in an Apple TB2-TB3 cable so I could keep on using with my 2017 iMac, only dedicated solely to BootCamp.

That is great info, thanks very much! My late 2013 iMac only has USB 3.0 and Thunderbolt 1, it seems pretty much impossible to get a TB1 enclosure for anything less than silly money so looks like a 3.0 one is my only option

$85 plus the price of a Thunderbolt cable seems fairly reasonable to me. :)

For booting the machine I highly recommend Thunderbolt over USB3 for the ability to enable TRIM.

TRIM commands do not work over USB on Macs, period. Garbage collection is not TRIM nor is it a replacement for it.
 
$85 equates to £61 here in the UK, which I would agree is not too bad - unfortunately, due to very high prices for EVERYTHING here in the UK it actually costs £113.64, equivalent to $158.20! Not such a good deal...

Cheers for the advice though :D
 
Thanks for the detailed reply, however are you sure that APFS is only supported on internal SSD as it is supported on my external 7200rpm drive that is connected by USB so why is SSD any different? I converted it to APFS only a couple of days ago using Disk Utility and the System report shows:
disk1s2:

Capacity: 4 TB (4,000,408,625,152 bytes)

BSD Name: disk1s2

Content: Apple_APFS

Supported vs possible are two different things.

The only configuration Apple currently supports APFS on boot drives is internal SSD, not Fusion, not HDD, and not external drives. Can you format external and other drives APFS? Yes, but you are on your own in terms of support from Apple. Will it work without issues? Again, good luck. For external drives being used for general storage, probably few issues, but then why. If you are adventuresome, cavalier, or curious, go ahead and try. But, there are clear warnings of issues including a number of articles on external APFS formatted drives being used as Time Machine destination. And you have to pause and ask why Apple doesn't convert other drives in the upgrade, clearly they are doing so out of an abundance of caution.

Don't mean to be flip about it, just sharing what Apple has said about the subject up to now.

The HS upgrade checks for internal SSD, and converts it to APFS, All other configs are left in HFS format. But, DU supports APFS formatting, albeit without warning which is probably an oversight on Apple's part.

Will they support APFS on other drives in the future? Probably, but they apparently feel there are enough "bugs" to warrant skipping the conversion at this time.
 
Again I suggest the Oyen Digital enclosure.

Don't worry about not having TRIM when booting and running a Mac via USB3.
I've been doing this for FIVE YEARS now, with no ill effects at all. I have booted and run my 2012 Mac Mini exclusively via USB3 since I unpacked it in January 2013. Running fine, using it now.

Another thought:
If you don't have the SSD yet, have you considered a "pre-packaged" USB3 SSD, such as the Samsung t5 or something like this:
http://www.amazon.com/exec/obidos/ASIN/B00ZTRY532?tag=delt-20

Right out-of-the-box, it should give you reads of about 430mbps and writes around 300-350mbps.
 
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$85 equates to £61 here in the UK, which I would agree is not too bad - unfortunately, due to very high prices for EVERYTHING here in the UK it actually costs £113.64, equivalent to $158.20! Not such a good deal...

Are there extremely high import taxes in the UK? Synchrotech does seem to offer international shipping and it probably wouldn't add that much to the price.
 
$85 equates to £61 here in the UK, which I would agree is not too bad - unfortunately, due to very high prices for EVERYTHING here in the UK it actually costs £113.64, equivalent to $158.20! Not such a good deal...

Cheers for the advice though :D

Would if be better to import from another country's distributer? Here is the list from Delock's web site.
http://www.delock.com/kaufen/distributoren.html
 
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Thanks for the advice, I decided to fit the ssd internally, which wasn’t too hard to do.

I will bear your suggestions in mind for the future though as I do have another machine that the kids use that could do with expansion.

Unfortunately the uk is a very 3xpensive place to live!
 
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