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Booting from external SSD...?

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Booting from external SSD...?

Postby Humble Bee » Sun Feb 17, 2019 11:58 pm

Hi all apples!

I wonder what the difference in performance would be between running and booting from the internal drive vs booting from an external TB3 SSD in a Mac mini (2018) with a 1Tb Samsung X5 setup?

Its just that i have the opportunity to get a mini (i7) at a good price but it only got a 256Mb SSD and i know I would need a bit more...

And is making a fusion drive out of the two (internal and external) a good solution?

Greatful for any insights... :thumbup:
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Re: Booting from external SSD...?

Postby Guido3 » Mon Feb 18, 2019 9:42 am

256GB is quite useable if you are careful. Can’t you simply use the internal SSD as the boot drive containing your programs etc...... and then use an external SSD for you content (Samples, audio etc....). Does the Mac have Thunderbolt or USB C? I have an external USB C SSD drive and it really quick.
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Re: Booting from external SSD...?

Postby Humble Bee » Mon Feb 18, 2019 10:53 am

Thanks Guido!

The Thunderbolt 3 ports on the Mac Mini 2018 might be USB-C compatible?

And 256Gb might be enough but I would like to have at least 512Gb... Thats what i run on my MB Air and I have about 150Gb to spare...

Still curious if booting from an external SDD on the thunderbolt 3 bus vs the internal SDD on the 2018 mac mini would be penalising the performance...? If so how much?
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Re: Booting from external SSD...?

Postby Guido3 » Mon Feb 18, 2019 2:11 pm

Humble Bee wrote:Still curious if booting from an external SDD on the thunderbolt 3 bus vs the internal SDD on the 2018 mac mini would be penalising the performance...? If so how much?

I have a bootable copy of my internal SSD on an external SSD (used for backup). If I can work out how to do it I'll try and give you an idea of how performance is affected (if at all). My MBP has Thunderbolt 3 / USB C , so sounds like it maybe similarly specced to your MacMini. My MBP has a 512GB SSD :D
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Re: Booting from external SSD...?

Postby Guido3 » Mon Feb 18, 2019 2:30 pm

By using Blackmagic, drive speeds are as follows.....

Internal SSD (512GB)
Write: 1850 MB/s
Read: 2400 MB/s

External SSD (G-Drive 512GB USB C)
Write: 300 MB/s
Read: 515 MB/s

Please take these finding with a pinch of salt but the results do seem to point towards using the internal drive rather than booting from an external. No doubt there are better external drives available (The Samsung T series get good reviews).

Maybe a TB3 external SSD is worth investigating. I would assume it would be pricey though.
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Re: Booting from external SSD...?

Postby Guido3 » Mon Feb 18, 2019 2:44 pm

I booted up via the external SSD and it was noticeably slower to boot from a cold start. However, when it had booted up, the system was quite snappy. I think you would notice a difference if you were doing lots of read/writing as the speeds are a lot slower with the external drive (see speeds on previous post).

Again, I am not an expert and by no means a power-user so please take these findings with a pinch of salt. I'm sure someone better placed with rock up shortly.

I would be interested in how quick the Samsung T series are compared to my G-Drive.
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Re: Booting from external SSD...?

Postby Humble Bee » Mon Feb 18, 2019 2:55 pm

Thank you for your effort here Guido!

I was looking at the Samsung X5 drive which is Thunderbolt 3. It would be a lot faster than USB-C I think. And more expensive as well... :)

I was a bit late so someone else snapped the
Mini up before me...

:thumbup:
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Re: Booting from external SSD...?

Postby ConcertinaChap » Mon Feb 18, 2019 3:16 pm

Humble Bee wrote:The Thunderbolt 3 ports on the Mac Mini 2018 might be USB-C compatible?

TB3 ports are always USB-C as well, so no problem there. There's one small gotcha with USB-C which doesn't get noticed much and that is USB-C Gen 2 (The Mac ports are Gen 2). This has significantly improved performance over vanilla USB-C and doesn't have the price penalty that TB3 external drives have - I've investigated those and gosh! they're fast but I don't have such a need for speed that I can justify the extra cost. Problem is that whether a drive's interface is Gen 2 or not is quite often buried in the small print.

When I got my iMac Pro I bought one of these and put two of these in it. The result is oodles of storage and plenty of access speed, surprisingly fast even when copying between the two drives in the housing.

CC
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Re: Booting from external SSD...?

Postby Humble Bee » Mon Feb 18, 2019 3:26 pm

Cheers CC!

TB3 seems to be 4 times faster than USB-c so if using an external drive to boot on the difference would be noticeable I guess.

Anyway, I missed the 2nd hand mini that was on sale here so I will wait a bit and pay some of my taxes and then have a go at a new one...

Cheers :thumbup:
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Re: Booting from external SSD...?

Postby Guido3 » Mon Feb 18, 2019 4:05 pm

ConcertinaChap wrote:
Humble Bee wrote:The Thunderbolt 3 ports on the Mac Mini 2018 might be USB-C compatible?

TB3 ports are always USB-C as well, so no problem there. There's one small gotcha with USB-C which doesn't get noticed much and that is USB-C Gen 2 (The Mac ports are Gen 2). This has significantly improved performance over vanilla USB-C and doesn't have the price penalty that TB3 external drives have - I've investigated those and gosh! they're fast but I don't have such a need for speed that I can justify the extra cost. Problem is that whether a drive's interface is Gen 2 or not is quite often buried in the small print.

CC

My MBP is USB C (Gen 2) as is the SSD external drive. Read speeds were not far off the manufacturers specs. I have checked specs of the Samsung T5 drives and they are around the same as my G-Drive so no point in me looking to change.

If TB3 speeds are up to 4x quicker, that is the way I would be looking to go.
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Re: Booting from external SSD...?

Postby ConcertinaChap » Mon Feb 18, 2019 4:43 pm

Guido3 wrote:If TB3 speeds are up to 4x quicker, that is the way I would be looking to go.

You may well not obtain 4 x faster speeds because long before then I strongly suspect you'll run into the maximum speed of the SSD/interface combination. So, to give a reductio ad absurdum example you would notice little difference moving a hard drive from a USB 3 enclosure to a TB 3 enclosure because the USB 3 bus would already be able to handle anything the drive could give to it.

What I'm trying to say is consider what you need the speed for. If you really need the fastest speeds possible, if you're rendering CGI for movies, perhaps, then by all means go TB3/NVMe. I'm just doing normal studio stuff and for that USB C Gen 2/SATA is giving me amply more than adequate speeds. It's your wallet :)

CC
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