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logicpro7

macrumors 6502a
Original poster
Sep 25, 2006
726
2
London UK
Hi,
Just bought a new 27" iMac... Is there a way to separate the SSD part of the Fusion drive to run the OS and my Music Apps, then use the HD part to store all my files and samples?

Would this be the best way to set up the iMac for music production?


Thanks.
 

tjwilliams25

macrumors 6502
Aug 10, 2014
316
60
Montana
You can manually dismantle the Core System Volume into the separate drives, yes, but it's probably not necessary for your application. macOS and all apps that you use, along with your most used files, are automatically stored on the SSD portion of the Fusion Drive by default. The HDD portion is for less-used files and larger bric-a-brak that's not speed intensive. I haven't noticed any slow down on my Fusion Drive and I've been doing a lot of video editing with my new iMac. Of course, your mileage may vary.
 

varian55zx

macrumors 6502a
May 10, 2012
748
260
San Francisco
I have the iMac 5K with 2tb fusion. I split that sucker

The fusion drive speed was good before but it is faster now. It's kind of a lot faster. You can definitely tell the difference when you are running off pure flash storage.

I kept my system information and apps on the SSD, and have all my iTunes media and other media on the HDD. Since that doesn't need to be on the SSD anyway, the split works well.

I'd recommend the split because I don't see any reason not to. It seems to be just better, and it's undeniably faster.

Apple used to sell SSDs and HDDs internally together but there was no fusion technology at that time. This mimics that experience, and I personally prefer it.
 

tubeexperience

macrumors 68040
Feb 17, 2016
3,192
3,897
I would return the 27" iMac with Fusion Drive and get the 27" iMac with 256GB SSD.

Then, I would add a Samsung 850 EVO.
 
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logicpro7

macrumors 6502a
Original poster
Sep 25, 2006
726
2
London UK
I would return the 27" iMac with Fusion Drive and get the 27" iMac with 256GB SSD.

Then, I would add a Samsung 850 EVO.
I bought it at a bargain price new and sealed £500 cheaper than in the Apple store, so returning it isn't an option.

I do have a Samsung 830 256GB SSD laying about.
 

logicpro7

macrumors 6502a
Original poster
Sep 25, 2006
726
2
London UK
I have the iMac 5K with 2tb fusion. I split that sucker

The fusion drive speed was good before but it is faster now. It's kind of a lot faster. You can definitely tell the difference when you are running off pure flash storage.

I kept my system information and apps on the SSD, and have all my iTunes media and other media on the HDD. Since that doesn't need to be on the SSD anyway, the split works well.

I'd recommend the split because I don't see any reason not to. It seems to be just better, and it's undeniably faster.

Apple used to sell SSDs and HDDs internally together but there was no fusion technology at that time. This mimics that experience, and I personally prefer it.
What speeds are you getting via Blackmagic Speed Test?

Where can i find the details to split the drive?


Thanks.
 

dimme

macrumors 68040
Feb 14, 2007
3,124
29,432
SF, CA
I split mine just to give it a go, but I ended up re fusing it. I am happy with the speed of the fusion drive. As it was said before splitting it up and running a pure SSD id faster, but for my usage it is better to have the large space and let the OS manage the files, it does a pretty good job.
 

varian55zx

macrumors 6502a
May 10, 2012
748
260
San Francisco
What speeds are you getting via Blackmagic Speed Test?

Where can i find the details to split the drive?


Thanks.
The speeds are reading the same as if you didn't split them, but let me offer some input on that.

If you run Blackmagic with the fusion, it's only measuring the SSD. So that is why the two read the same.

However, with the fusion drive, you aren't only using the SSD of course. You're using that disgusting little HDD too.

The fusion drive, in many ways as it is a great system, uses a block system. That means blocks of files are stored on the HDD and blocks are stored on the SSD. Obviously, any blocks on the HDD are read slow as molasses, and any blocks on the SSD are read lightning fast.

Because some blocks of nearly every file are on the HDD, that will be why your fusion won't be operating at the same speed that black magic reads. If you split them you will more or less get those speeds.
 

logicpro7

macrumors 6502a
Original poster
Sep 25, 2006
726
2
London UK
Ok thanks.

I only use the iMac for video editing & music production... So FCPX, Logic X, Ableton, & various plugins.

Do you think it would be better to use a SSD in an external case connected via Thunderbolt, running the OS and Apps?
 

varian55zx

macrumors 6502a
May 10, 2012
748
260
San Francisco
Do you think it would be better to use a SSD in an external case connected via Thunderbolt, running the OS and Apps?
No and no.

Not at all

An SSD in an external case connected via Thunderbolt would be slower than the super fast internal PCIe SSDs that Apple provides. The external SSD would be noticeably slower, and would pale in comparison.

We are talking about some serious speed from these wonderful internal PCIe SSDs.

In addition, the external SSD is prone to disconnecting. One gentle bump to your desk by accident and it disconnects. Additionally, sometimes they just randomly disconnect on their own.

I advise against that.
 

varian55zx

macrumors 6502a
May 10, 2012
748
260
San Francisco
Yeah just fit the Mac at the time of order with the 256, 512, or 1tb SSD for your storage option at the time of order.

The 2 tb fusion also comes with 128gb of the same fast SSD storage.
 

Fishrrman

macrumors Penryn
Feb 20, 2009
28,728
12,840
OP wrote above:
"I only use the iMac for video editing & music production... So FCPX, Logic X, Ableton, & various plugins."

Pardon me if I've missed it, but is your iMac the "1tb fusion" model, or the "2tb fusion" model?
The difference is important.

If it's a 1tb fusion model, it has only a 24gb SSD portion (of the fusion drive) inside.
If it's a 2tb fusion model, it has a 128gb SSD and a 2tb HDD.

If it's a 2tb model, I suggest this:
1. Split the fusion drive into separate SSD and HDD
2. Put your OS and apps on the SSD
3. Keep your other files on the HDD (or better -- connect the 256 external SSD via USB3 and use that instead)

If it's a 1tb model, I suggest this:
1. Leave the internal fusion drive alone.
2. Take the external 256gb SSD you have, and create an "external booter". Again, USB3 will be fine. You -can- get a thunderbolt enclosure for it, but the enclosure alone costs around $90.
2a. Put your OS, apps, account, etc onto the external booter
3. Put your music libraries and production files on the internal fusion drive.

Either way above should give you the fastest speeds and fewest "bottlenecks", insofar as data input/output are concerned...
 

logicpro7

macrumors 6502a
Original poster
Sep 25, 2006
726
2
London UK
OP wrote above:
"I only use the iMac for video editing & music production... So FCPX, Logic X, Ableton, & various plugins."

Pardon me if I've missed it, but is your iMac the "1tb fusion" model, or the "2tb fusion" model?
The difference is important.

If it's a 1tb fusion model, it has only a 24gb SSD portion (of the fusion drive) inside.
If it's a 2tb fusion model, it has a 128gb SSD and a 2tb HDD.

If it's a 2tb model, I suggest this:
1. Split the fusion drive into separate SSD and HDD
2. Put your OS and apps on the SSD
3. Keep your other files on the HDD (or better -- connect the 256 external SSD via USB3 and use that instead)

If it's a 1tb model, I suggest this:
1. Leave the internal fusion drive alone.
2. Take the external 256gb SSD you have, and create an "external booter". Again, USB3 will be fine. You -can- get a thunderbolt enclosure for it, but the enclosure alone costs around $90.
2a. Put your OS, apps, account, etc onto the external booter
3. Put your music libraries and production files on the internal fusion drive.

Either way above should give you the fastest speeds and fewest "bottlenecks", insofar as data input/output are concerned...
Ahh yes sorry 1TB Fusion
 

logicpro7

macrumors 6502a
Original poster
Sep 25, 2006
726
2
London UK
Yeah just fit the Mac at the time of order with the 256, 512, or 1tb SSD for your storage option at the time of order.

The 2 tb fusion also comes with 128gb of the same fast SSD storage.
Already bought the iMac secondhand, but sealed.

1TB Fusion, MK472 model
 

tubeexperience

macrumors 68040
Feb 17, 2016
3,192
3,897
Already bought the iMac secondhand, but sealed.

1TB Fusion, MK472 model

Holy ****! That's expensive!

If I want to buy an iMac, I would buy one with 1TB HDD and replace the drive with a 1TB Samsung 850 EVO or buy one with the 256GB SSD and then add a 500GB Samsung 850 EVO.
 

varian55zx

macrumors 6502a
May 10, 2012
748
260
San Francisco
Since you have the one with the 1 tb fusion the best thing for you to do would actually be to install a third party SSD internally.

Since I don't want to take the risk of opening it as well as take on the difficulty of the task, I'd pay a 3rd party professional to do it.
 

maflynn

macrumors Haswell
May 3, 2009
73,682
43,717
Since you have the one with the 1 tb fusion the best thing for you to do would actually be to install a third party SSD internally.
Or use an external SSD running off an USB 3.0 interface.

I'm doing that right now and the speeds are good. I need to use different Operating systems, and so I have one installed on an external disk and its very fast. I'd opt for that over opening up a new iMac
 

varian55zx

macrumors 6502a
May 10, 2012
748
260
San Francisco
Or use an external SSD running off an USB 3.0 interface.

I'm doing that right now and the speeds are good. I need to use different Operating systems, and so I have one installed on an external disk and its very fast. I'd opt for that over opening up a new iMac
That's fair, however if you are paying a professional I think that is a responsible decision and route.

Apparently it doesn't necessarily void your warranty. This is something I did not know.

The external SSD thing is nice until you bump it an disconnects from your computer. That's a workable option too, obviously it's going to be best to get it right the first time and pick the adequate option when you buy it.
 

maflynn

macrumors Haswell
May 3, 2009
73,682
43,717
That's fair, however if you are paying a professional I think that is a responsible decision and route.
I'm not knocking that, in fact I may very well opt for that route myself once my warranty expires but the option to just use an external drive is the most simplest.
 

varian55zx

macrumors 6502a
May 10, 2012
748
260
San Francisco
That's fine, however the whole reason I am now more on board with this route than before is the fact that it doesn't even necessarily void your warranty.

That said there is still a chance, so waiting until it's over is optimal.

Apple only provides a 1 year warranty which is not exactly a long time.
 

Samuelsan2001

macrumors 604
Oct 24, 2013
7,729
2,153
Or just use the machine as it is. The 1tb fusion only has a 24gb cache of flash storage and not a proper 128gb SSD as was the case previously. This is pointless to split up there is not enough space for everything you'll want on that tiny flash drive.
 
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