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I Need a Drink

macrumors regular
Original poster
Oct 14, 2013
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I have been researching getting an SSD for both my iMac and Mac Mini for system drives. After reading a lot of info, I don't think that the performance difference means enough to me to bother with opening the iMac or the Mini and I've decided to go external via USB3.

I have decided to go with either the Samsung EVO 850 in an external USB3 enclosure (with UASP) or the Samsung T3 external SSD. Price wise, the EVO plus enclosure would cost about the same as the T3 and I believe that the internals of the drives are similar. Any reason not to just use an external SSD vs an internal in an enclosure?

Thanks.
 
I could be wrong but i think you can't use TRIM on the T3. I know for sure you can on the Evo 850 but i don't know if it is limited to sata (so internal) or if you can also enable it when connected with usb/thunderbolt.
 
You cant use Trim on any USB connection, so neither would enable Trim. But both have garbage collection so that would negate an advantage to either one. A good USB 3.0 enclosure is around $20. I think it comes to personal preference between the 2 for external hard drive choice. I have both a WD 1TB USB3.0 Mybook and a 275GB SSD Crucial in a USB 3.0 enclosure.

I think the only advantage of having an enclosure is if you can get cheaper laptop SSD's present or down the road. I got $84 into my 275GB SSD external hard drive using an enclosure.
 
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You cant use Trim on any USB connection, so neither would enable Trim. But both have garbage collection so that would negate an advantage to either one. A good USB 3.0 enclosure is around $20. I think it comes to personal preference between the 2 for external hard drive choice. I have both a WD 1TB USB3.0 Mybook and a 275GB SSD Crucial in a USB 3.0 enclosure.

I think the only advantage of having an enclosure is if you can get cheaper laptop SSD's present or down the road. I got $84 into my 275GB SSD external hard drive using an enclosure.
Correct... no TRIM over USB for OS X.

For OP's setup I would prefer a separate enclosure with a SSD to allow more flexibility later. For example, if you buy a new MacBook Pro later you can always swap the SSD over into a USB-C enclosure.
 
Thanks for the info. One more question. Regardless of which drive I go with, when I format them with Disk Utility, will I be removing the built in garbage collection on them?
 
OP asked:
"Any reason not to just use an external SSD vs an internal in an enclosure?"

I've posted this numerous times, but I'll post it again.
I've been booting and running my late-2012 Mac Mini via an SSD mounted in a USB3/SATA dock for almost 4 years now. Runs great.
TRIM has NEVER been enabled. Still runs great.
Runs as smoothly and as quick today as when I first set it up.
TRIM, for all practical purposes, doesn't matter.

However, I recommend against using a Samsung drive.
This is my opinion only and it's not shared by the majority of users here.
Instead, I'd recommend something like this:
http://www.amazon.com/exec/obidos/ASIN/B00ZTRY532?tag=delt-20

Set your USB3/SSD to have your OS, your apps, and your home folders, BUT...
... keep LARGE libraries of stuff (music, pics, movies) on the internal HDD.
This will keep the SSD lean and clean, with plenty of free space left over.

Again, the notion of TRIM is akin to the "McGuffin" in a Hitchcock movie.
A matter of little or no importance.

But give an external boot SSD a try, and GET BACK TO US.
You'll quickly see how easy it is, and what a great performance boost you'll get.
 
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OP asked:
"Any reason not to just use an external SSD vs an internal in an enclosure?"

I've posted this numerous times, but I'll post it again.
I've been booting and running my late-2012 Mac Mini via an SSD mounted in a USB3/SATA dock for almost 4 years now. Runs great.
TRIM has NEVER been enabled. Still runs great.
Runs as smoothly and as quick today as when I first set it up.
TRIM, for all practical purposes, doesn't matter.

TRIM does matter, as it more effectively utilizes garbage collection. There are ways around TRIM that can end in a similar result. This means sacrificing a lot of free, unallocated space on the SSD (20%-30%), leaving the drive idle for periods of time to allow garbage collection to do its work, and actively reducing the number of writes and deleted files. TRIM allows a drive to be 10% or 90% full with no significant loss of performance. You will see massive degradation in an SSD 90% full over USB 3.0. So, yes, TRIM does matter, but there are ways around its use
 
Thanks for the help everyone. I ended up finding (what I think) is a pretty good deal on 2 EVO 850 drives, one for my iMac and another for my Mini, for $134.99 each for the 500GB version.

This way I can go USB3 for now and if I decided to go Thunderbolt later I can enable TRIM. Can anyone recommend a good, inexpensive, USB3 enclosure for these drives?

Thank you.
 
I'm on mobile so can't link, but go to Amazon and search for Inatech uasp and you will find one lots of us like. I think it is around $18.
 
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