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Big Ron

macrumors 6502
Original poster
Dec 7, 2012
425
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United Kingdom
Hi

Just taken delivery of my BTO 27" iMac and was wondering how to best connect my external SSD. Does any of you learned ladies or gents have any direct experience with hooking up an external SSD via USB 3 or USB C? I have a spare SSD that I wan't to connect but not sure of which external closure to buy.

Also is it worth paying that little bit extra for a genuine Apple USB C cable or is a third party one good enough not to compromise transfer rates? Thanks in advance.
 
Hi

Just taken delivery of my BTO 27" iMac and was wondering how to best connect my external SSD. Does any of you learned ladies or gents have any direct experience with hooking up an external SSD via USB 3 or USB C? I have a spare SSD that I wan't to connect but not sure of which external closure to buy.

Also is it worth paying that little bit extra for a genuine Apple USB C cable or is a third party one good enough not to compromise transfer rates? Thanks in advance.

A proper USB C enclosure/controller should operate under USB 3.1 standard allowing for a theoretical maximum of 10 GBit/Sec. If your SSD is SATA-3, it theoretically will max out at 6 Gbit/Sec. A USB 3.0 enclosure/controller will max out at 5 GBit/Sec which could theoretically bottleneck a fast SSD.

The question would be, how fast is your SSD to begin with? what is its rated speed? if it's a fast drive, find a USB-C enclosure with full USB 3.1 support and you should be game.

http://www.anandtech.com/show/10708/satechi-and-startech-usb-31-gen-2-typec-hddssd-enclosures-review

The only time you would need a proper Apple cable, is if you intend to charge an 85watt MBP 15inch. If you do not intend to pass through charge your MBP, a good enclosure with a cable is all you'll need.
 
Mac Doctor wrote:
"A proper USB C enclosure/controller should operate under USB 3.1 standard allowing for a theoretical maximum of 10 GBit/Sec."

Hold on a minute.
Aren't there TWO "levels" of USB3.1 ?

There's a USB3.1 "gen1" spec that still has the limit of 5gb/sec;
and...
... a USB3.1 "gen2" spec that ups the throughput to 10gb/sec.

Or... do I have that wrong?
 
I'm not clear about the size and rated speed of your SSD drive. But for my new iMac I bought an Inateck USB-C enclosure to use with a 2.5 inch Western Digital hard drive. It is nicely finished and comes with a short 8 inch cable with a USB-C plug that plugs into the Mac. Have if velcroed to the back of the iMac stand and it is working fine for TimeMachine backup. $20 at Amazon:

https://www.amazon.com/Inateck-Encl....1+2.5-inch+External+HDD+Hard+Drive+Enclosure
 
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Thanks colodane, that just looks what I need, I have just checked the UK Amazon site and they have them in stock.

The only question now is will it be quicker than my existing USB connection?

When did it get so difficult?
 
For me I went with normal USB-3 enclosure from Lacie porsche design p9220, it is very nicely finished and 5Gbit/s is plenty of speed for me.
 
A proper USB C enclosure/controller should operate under USB 3.1 standard allowing for a theoretical maximum of 10 GBit/Sec. If your SSD is SATA-3, it theoretically will max out at 6 Gbit/Sec. A USB 3.0 enclosure/controller will max out at 5 GBit/Sec which could theoretically bottleneck a fast SSD.

My 27" iMac shows a USB 3.0 bus in the System Report so would I see any difference in actual performance between a 3.0 and a 3.1 enclosure ?

Thanks


EDIT : Just took a look at the Apple web site and see that the Thunderbolt ports in the iMac will support USB 3.1 so I guess if we have a USB 3.1 enclosure we should connect it to the Thunderbolt port and not the USB port.
 
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Don't get an enclosure for a separately added SSD unless it can be also powered by external power. It's quite common to run into problems with stability with DIY external enclosure+SSD setups when running only on bus power. It doesn't happen to everyone of course, but nonetheless it's quite common. In fact, the only time I'd consider getting a bus powered drive is if it is a name brand pre-built bus-powered drive, as they are specifically designed to work this way.

Also note that USB drives have no TRIM support. If a USB SSD gets near full, it can slow to a crawl, sometimes even to speeds that are slower than hard drives, believe it or not.
 
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I have my Samsung 850 evo using a Sabrent SATA to USB adapter plugged into a thunderbolt port using this aukey adapter. I get 400/420MB write/read speeds.
KentuckyApple that seems reasonable that may be the way ahead, thanks
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Don't get an enclosure for a separately added SSD unless it can be also powered by external power. It's quite common to run into problems with stability with DIY external enclosure+SSD setups when running only on bus power. It doesn't happen to everyone of course, but nonetheless it's quite common. In fact, the only time I'd consider getting a bus powered drive is if it is a name brand pre-built bus-powered drive, as they are specifically designed to work this way.

Also note that USB drives have no TRIM support. If a USB SSD gets near full, it can slow to a crawl, sometimes even to speeds that are slower than hard drives, believe it or not.
That's interesting, I though Sierras had built in trim support for third part SSds?
 
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