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How well does an external SSD-USB work in real life?

M

mortenjensen

macrumors regular
Original poster
Mar 19, 2012
236
18
Hi all,
I am considering exchanging my old macbook pro + external monitor with a 27'' iMac. I currently have a 512 SSD installed, which is room enough.
There is quite a difference price wise between a 256 GB and a 512 GB SSD solution. So my thinking: I could convert my 512 SSD into a secondary hard drive in a USB 3.0 box or even a USB-c box. As I understand it, the first one will transfer with 5 gb speed and the last with 10 gb speed - if my SSD can handle that amount of data (it is a standard SATA 6.0 running around 600 mb/s on a blackmagic test).

Has anyone such a setup going? How well does it work? It will be absolutely silent, of course. A 256 GB main SSD would be enough for all my programs and the external 512 enough for all my data.

Would I be able to notice the difference with such high speeds on USB 3.0 and USB-c?

Thanks,
Morten
 
iMac 21" 2012, USB 3.0
External SSD drive: Transcend MTS800S M.2 2280 128Gb SATA III MLC TS128GMTS800S
SSD USB enclosure: Transcend TS-CM80S, M.2, USB 3.1 (TS-CM80S)
High Sierra works great. Blackmagic Disk Speed Test read/write speed: 420 MB/s
 
The outboard USB drive will almost certainly be SATA 3, so you aren't going to be able to get it to run at 10 Gbit/sec no matter what. You'll see close to SATA 3 speeds minus a wee bit of USB overhead, sergeyz's number looks about right.

The internal iMac SSD is not SATA and runs a lot faster -- exactly how much faster, I'm not sure.

Will you notice the difference? probably sometimes. Will it be a very large perceived difference? Probably not, except in very specific use cases like reading or writing very large sequential files.

By the way, USB C is an connector definition, not a speed definition. It gets mixed up with USB 3.x because it was introduced with the USB 3.0 specification. If you want to talk about speeds, the most precise wording is USB 3.1 Gen 1 (same as the original USB 3.0) and USB 3.1 Gen 2, 5 Gbit and 10 Gbit/sec respectively.

edited to add: I've never heard of an SSD that speaks "native" USB protocol. I'm mildly surprised that nobody has done it; perhaps the USB-to-SATA interface is so inexpensive that it's not worth the effort on the SSD controller side?
 
The question:
"How well does an external SSD-USB work in real life?"

My answer, based on personal experience:
Very well indeed.

I've been booting and running my late 2012 Mac Mini from an SSD in a USB3 docking station since the day I took it out of the box in January 2013.

It ran very well then, and it continues to do so today, going on 5 years later.
I daresay I have more experience at doing this than any other poster in this forum.

Having said that...

There is NO WAY an externally-connected USB3 SSD can compare to the INTERNAL SSD's that Apple is installing into their iMac line. Not even close. Realize that before you begin.

But... for "extra external storage" (NOT the boot drive), an SSD in a USB3 enclosure (that supports UASP) should yield read speeds of 420-430mbps and writes in the 350mbps range. That's still very good (those are the speeds I get booting/running from an external SSD).

So... re your question:
"How well does it work? It will be absolutely silent, of course. A 256 GB main SSD would be enough for all my programs and the external 512 enough for all my data."

I think that will work very well.
Use the internal SSD for the OS, apps, and your basic accounts.
Use the external USB3 SSD for storage of larger libraries (movies, music, pictures).

Once set up properly, I doubt you'll have any complaints.
 
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Thanks, these replies are most helpful! It looks like a USB3 docking station will give me over 400 mbps with my 500 GB SATA 3 drive (Samsung SSD evo 840). This would be fine for iTunes library, photos and documents.

Btw: Will most new docking enclosures support UASP? I did not know about this protocol, but searching for it tells me that this info is not regularly provided by vendors. An enclosure costs in the range of $10-20, so they are really cheap. But they need to support the lastet protocols, of course.

Thanks again!
Morten
 
I've been running on an external SSD for well over a year maybe two. I just decided to move back to the internal drive array for various reasons.

I had windows installed on the internal ssd, but mojave whacked that, and then mojave corrupted my external ssd, so in rebuilding my iMac I opted to forego using windows and just go back to a stock configuration. Sorry that I digressed a bit, but I was very happy with the running off of a Samsung T3, I know they're up to a T5 now.
 
OP:

MAKE SURE that any external USB3 device you buy -- whether it be an enclosure or USB3/SATA dock -- is SPECIFICALLY STATED to support "UASP" (USB attached SCSI protocol".

Unless you have this, you may not get the fastest speeds that are possible.

I believe that -most- USB3 storage devices sold today incorporate this. But some do not. It's up to you to check them carefully before buying.
 
Fishrrman said:
"UASP" (USB attached SCSI protocol"
Click to expand...
This.
There are lots of choices, so the hard part os wading through reviews and specs.

My suggestion for a semi-permanent disk is to put it in a real enclosure, not a dock. While SSDs are essentially shock (whack) proof, the connection still has a bit of wiggle when connected in a dock. OK for ad-hoc. Less than ideal for long term.
 
mortenjensen said:
Would I be able to notice the difference with such high speeds on USB 3.0 and USB-c?
Click to expand...

Probably not, but having the larger internal 512GB is likely money well spent. Especially down the road if you decide to sell it, as you will recoup some of that money.
 
How well does an usb enclosure equipped with a ssd work on a MBAir?
I have a 64 gg ssd Drive I monthly swap to run mountain lion OS X so I can scan, surf and smile.
 
It works great.

My wife has been running the OS from an USB3 SSD drive for 2 years now.
 
pier said:
It makes no sense to do this. A SATA SSD will run at the same speeds as USB3.

Get an SSD, put it in a USB3 case, done. No need to open the iMac.
Click to expand...

TRIM and Boot Camp are not supported on external drivers.

Furthermore, installing you SSD provide far more reliability: the SSD cannot be accidentally unplugged while using.
 
mreg376 said:
I agree. Opening up the new iMac will cause Apple to decline repairs under warranty.
Click to expand...

Sigh. Not this again. Apple might decline a repair solely because you opened the box, but if they do, they're breaking the law, at least in the US. They were warned (in writing) against Magnuson-Moss violations fairly recently and I'd expect them to obey.

But to address the original question, the external drive is the simplest solution and you won't lose any speed. I don't think you're likely to miss TRIM unless your workload consists of regular massive writes that write a significant fraction of the SSD. You may (or may not) have occasional wake-from-sleep issues where the drive doesn't remount and you have to fiddle with it, but I think with SSD those issues are rare. I'd install it internally only if you're comfortable with the opening procedure, can follow directions and have reasonably steady hands, and are only truly happy when things are done "right". :)
 
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Make life simpler for yourself and rather than fooling with an enclosure and all that, simply purchase an already-packaged external SSD, such as Samsung's excellent T5 series. You can get them in various capacities: 250 GB, 500 GB, 1 TB and 2 TB. No, not inexpensive but sturdy and very fast, probably much faster than trying to use your old SSD in an enclosure.
 
kschendel said:
Sigh. Not this again. Apple might decline a repair solely because you opened the box, but if they do, they're breaking the law, at least in the US. They were warned (in writing) against Magnuson-Moss violations fairly recently and I'd expect them to obey.
Click to expand...

Did I mention that I love beating dead horses? :) Actually, neither Apple nor any other computer manufacturers were warned about the Magnuson-Moss issue -- if you read the article is was only certain video game manufacturers, cellular phone manufacturers, and something else I cannot recall but no computer manufacturers. And that is because Magnuson does not prohibit a manufacturer from deciding which parts in devices it sells are user-upgradeable -- only that it cannot restrict what parts to use when they are user-upgradeable. The bottom line is that Apple can and DOES decline warranty work, legally or not, in almost all cases I've ever heard if they determine that the machine was opened, so I do think it is important for users here to understand what they're in for with Apple when considering advice thrown around on this forum to "just buy an entry level iMac and then open it up and put in what you want."

And as to the original issue here, I agree with you that an external SSD is the way to go. I've been using external drives with no problem on and off for several years. Fast, reliable and portable.
 
mreg376 said:
I agree. Opening up the new iMac will cause Apple to decline repairs under warranty.
Click to expand...

Opening one's Mac does not void the warranty.

From the FTC:

The letters warn that FTC staff has concerns about the companies’ statements that consumers must use specified parts or service providers to keep their warranties intact. Unless warrantors provide the parts or services for free or receive a waiver from the FTC, such statements generally are prohibited by the Magnuson-Moss Warranty Act, a law that governs consumer product warranties. Similarly, such statements may be deceptive under the FTC Act.

Each company used different language, but here are examples of questionable provisions:

  • The use of [company name] parts is required to keep your . . . manufacturer’s warranties and any extended warranties intact.
  • This warranty shall not apply if this product . . . is used with products not sold or licensed by [company name].
  • This warranty does not apply if this product . . . has had the warranty seal on the [product] altered, defaced, or removed.
“Provisions that tie warranty coverage to the use of particular products or services harm both consumers who pay more for them as well as the small businesses who offer competing products and services,” said Thomas B. Pahl, Acting Director of the FTC’s Bureau of Consumer Protection.
Click to expand...

From MacSales/OWC:

Unfortunately though, there exists a misconception among some users and even technicians that opening the machine voids the warranty.

We address this topic directly with customers via our support portals and are happy to inform you here of the same fact: upgrading your Mac does not void its warranty.

This consumer protection is owed to the little known Magnuson-Moss Warranty Act of 1975. Put simply, the act states that a company can’t require you to upgrade with only its own branded parts to retain the warranty. This important act protects your rights as a consumer and allows you to install upgrades with peace of mind confidence.

However, the warranty doesn’t cover any damage incurred while installing upgrades.
Click to expand...
 
This does not apply to the Apple warranty situation, those cited FTC letters were, by their own terms, not sent to any computer manufacturers, and Apple regularly refuses to work on any machine that it determines was opened by a non-authorized service provider. This is true whether the opposite is said once, or 50 times. MacSales/OWC is an authorized Apple reseller.
 
mreg376 said:
This does not apply to the Apple warranty situation, those cited FTC letters were, by their own terms, not sent to any computer manufacturers, and Apple regularly refuses to work on any machine that it determines was opened by a non-authorized service provider. This is true whether the opposite is said once, or 50 times. MacSales/OWC is an authorized Apple reseller.
Click to expand...

Section 102 (c) of Magnuson-Moss Warranty Act

(c) No warrantor may condition the continued validity of a warranty on the use of only authorized repair service and/or authorized replacement parts for non-warranty service and maintenance (other than an article or service provided without charge under the warranty or unless the warrantor has obtained a waiver pursuant to section 102(c) of the Act, 15 U.S.C. 2302(c)). For example, provisions such as, “This warranty is void if service is performed by anyone other than an authorized ‘ABC’ dealer and all replacement parts must be genuine ‘ABC’ parts,” and the like, are prohibited where the service or parts are not covered by the warranty. These provisions violate the Act in two ways. First, they violate the section 102(c), 15 U.S.C. 2302(c), ban against tying arrangements. Second, such provisions are deceptive under section 110 of the Act, 15 U.S.C. 2310, because a warrantor cannot, as a matter of law, avoid liability under a written warranty where a defect is unrelated to the use by a consumer of “unauthorized” articles or service. In addition, warranty language that implies to a consumer acting reasonably in the circumstances that warranty coverage requires the consumer’s purchase of an article or service identified by brand, trade or corporate name is similarly deceptive. For example, a provision in the warranty such as, “use only an authorized ‘ABC’ dealer” or “use only ‘ABC’ replacement parts,” is prohibited where the service or parts are not provided free of charge pursuant to the warranty. This does not preclude a warrantor from expressly excluding liability for defects or damage caused by “unauthorized” articles or service; nor does it preclude the warrantor from denying liability where the warrantor can demonstrate that the defect or damage was so caused.
Click to expand...
 
Apple regularly refuses to work on any machine that it determines was opened by a non-authorized service provider. This is true whether the opposite is said once, or 50 times.
 
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mreg376 said:
Apple regularly refuses to work on any machine that it determines was opened by a non-authorized service provider. This is true whether the opposite is said once, or 50 times.
Click to expand...

Apple regularly refuses to work on any machine that it determines was damaged by a non-authorized service provider.

This is in compliant with the Section 102 (c) of Magnuson-Moss Warranty Act which said:

(c) No warrantor may condition the continued validity of a warranty on the use of only authorized repair service and/or authorized replacement parts for non-warranty service and maintenance (other than an article or service provided without charge under the warranty or unless the warrantor has obtained a waiver pursuant to section 102(c) of the Act, 15 U.S.C. 2302(c)). For example, provisions such as, “This warranty is void if service is performed by anyone other than an authorized ‘ABC’ dealer and all replacement parts must be genuine ‘ABC’ parts,” and the like, are prohibited where the service or parts are not covered by the warranty. These provisions violate the Act in two ways. First, they violate the section 102(c), 15 U.S.C. 2302(c), ban against tying arrangements. Second, such provisions are deceptive under section 110 of the Act, 15 U.S.C. 2310, because a warrantor cannot, as a matter of law, avoid liability under a written warranty where a defect is unrelated to the use by a consumer of “unauthorized” articles or service. In addition, warranty language that implies to a consumer acting reasonably in the circumstances that warranty coverage requires the consumer’s purchase of an article or service identified by brand, trade or corporate name is similarly deceptive. For example, a provision in the warranty such as, “use only an authorized ‘ABC’ dealer” or “use only ‘ABC’ replacement parts,” is prohibited where the service or parts are not provided free of charge pursuant to the warranty. This does not preclude a warrantor from expressly excluding liability for defects or damage caused by “unauthorized” articles or service; nor does it preclude the warrantor from denying liability where the warrantor can demonstrate that the defect or damage was so caused.
Click to expand...
 
Yes, that's true too. But Apple regularly refuses to work on any machine that it determines was opened by a non-authorized service provider. People should understand this before listening to advice that simply says their warranty "cannot be voided," which even if technically true, won't help them. Most people don't want to go from an Apple store into a lawsuit, at the same time being stuck with a broken iMac.
 
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