SSD vs Fusion Drive

Falcon80

macrumors 6502
Original poster
Oct 27, 2012
373
94
Given a choice, would you guys get a 512 SSD (smaller storage, cost more, faster) vs 2 TB Fusion (bigger storage, cost less, much slower?) and why?

For my use cases, I will be using the iMac to do development (pretty huge projects).
- Xcode,
- Android Studio,
- Unity

and some photo editing
- Photoshop,
- Illustrator

also running VMs for Windows and Linux.

Thanks!
 

Floris

macrumors 68020
Sep 7, 2007
2,381
1,451
Netherlands
There are three reasons why I will not buy a fusion drive.

One, almost everybody in the creative world that I talk to, their first response is: Don't - Just go with SSD.
Two, The page for the FD says: 2tb and 3tb models both have 128gb SSD for OS and macOS auto handles what happens with this drive basically .. and you get the best performance out of if you setup your system with 32gb ram.
Three, we are in a thunderbolt3 and usb-c world now, external ssd drives on 1, 5, 10 gbit speeds, yes pls.
The SSD we get without a big storage internal on HDD (not ssd) means less warm, less noise, way faster chip, and we get to really decide what goes on the drive and not. Not just macOS saying "this is a frequently used file, we will use the ssd to help with the cache" ..
 

iMi

macrumors 65816
Sep 13, 2014
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Both options obviously offer some advantages and disadvantages. As a general rule, I always go for speed vs capacity because it's usually easier and cheaper to add capacity but impossible to add more speed later without replacing the drive.

On the other hand, this is an iMac, so any additions would have to be external (unless you really feel comfortable
opening it up). You'll have to decide if they extra speed is worth the limitations in internal storage. If you're comfortable adding external storage down the road and don't mind it, then you should go for the speed. It could seriously impact your workflow.

That's just my opinion. Hope it helps.
 

drew.bowser

macrumors regular
Sep 23, 2008
106
8
Missouri
My 2015 iMac (middle tier with 1tb fusion drive) was slower than my 2014 iMac (Base tier with 1 tb fusion drive)

The fusion drives with 32 or less SSD are jokes. My 2014 iMac reads 1.1GB/S black magic disk test where my 2015 (with NOTHING on it) reads around 135MB/S....

Needless to say that I just started the return process! IF you get a fusion drive it needs to be 2tb or higher...Id rather have a 512gb SSD....
 

iMi

macrumors 65816
Sep 13, 2014
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I forgot to add an important point.

The SSD will almost certainly last much, much longer and will be less likely to fail prematurely. This could be an important advantage given that the iMac is glued together and not particularly repairable.
 

Falcon80

macrumors 6502
Original poster
Oct 27, 2012
373
94
There are three reasons why I will not buy a fusion drive.

One, almost everybody in the creative world that I talk to, their first response is: Don't - Just go with SSD.
Two, The page for the FD says: 2tb and 3tb models both have 128gb SSD for OS and macOS auto handles what happens with this drive basically .. and you get the best performance out of if you setup your system with 32gb ram.
Three, we are in a thunderbolt3 and usb-c world now, external ssd drives on 1, 5, 10 gbit speeds, yes pls.
The SSD we get without a big storage internal on HDD (not ssd) means less warm, less noise, way faster chip, and we get to really decide what goes on the drive and not. Not just macOS saying "this is a frequently used file, we will use the ssd to help with the cache" ..
For an external SSD drive (TB3 or USB-C), any idea if we will be able to run development projects directly on it without transferring to iMac first? Or purely just for storing images/videos or other non working files?
 

trsblader

macrumors 6502
May 20, 2011
422
158
For an external SSD drive (TB3 or USB-C), any idea if we will be able to run development projects directly on it without transferring to iMac first? Or purely just for storing images/videos or other non working files?
It will be able to handle that no problem I believe. Unsure how much you're doing in xCode vs Unity be we developed in Unity and only exported to xCode for uploading. Very often had photoshop and unity going simultaneously with no issues. This was all inside a Windows VM on Parallels running Visual Studio + debugging tools. Ours was just a little USB 3 SSD off Amazon we velcro'd to the back of the iMac and for the price I doubt it was anywhere near as fast as some of Samsung's SSD's.
 
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Floris

macrumors 68020
Sep 7, 2007
2,381
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Netherlands
For an external SSD drive (TB3 or USB-C), any idea if we will be able to run development projects directly on it without transferring to iMac first? Or purely just for storing images/videos or other non working files?
I don't see why it has to be transferred first.
 

Falcon80

macrumors 6502
Original poster
Oct 27, 2012
373
94
I don't see why it has to be transferred first.
Just wondering if it has a major impact speed wise if the files are in a external drive.
[doublepost=1496890425][/doublepost]
It will be able to handle that no problem I believe. Unsure how much you're doing in xCode vs Unity be we developed in Unity and only exported to xCode for uploading. Very often had photoshop and unity going simultaneously with no issues. This was all inside a Windows VM on Parallels running Visual Studio + debugging tools. Ours was just a little USB 3 SSD off Amazon we velcro'd to the back of the iMac and for the price I doubt it was anywhere near as fast as some of Samsung's SSD's.
Thanks for the information!
 

deany

macrumors 68030
Sep 16, 2012
2,874
2,067
North Wales
I seem to remember there is a difference in the fusion drives, the base model having less SSD portion I think...which wasn't made clear by Apple.

I'd always go SSD, even as previously mentioned just for reliability factor...no moving parts.
 

Tjmckay4

macrumors member
Apr 24, 2014
92
22
Perth, West Aus
What about having the 2tb fusion and an external SSD for the OS and apps?

On my 27" 2011 iMac, I have a 120gb Samsung 850 evo (plugged into a TB seagate adapter) for the OS and apps. I use the internal 3tb seagate HD for the data.
 

flyinmac

macrumors 68040
Sep 2, 2006
3,582
2,408
United States
I would avoid a fusion drive no matter what.

I would choose either a SSD or a fast spinner.

The reason is that you increase your odds of failure by spanning a volume over two drives.

If either drive fails, you automatically lose the data on both drives, even the one that didn't fail.

Additionally, there have been a lot of people who've had the "fusion" fail. Which presents the same problem. Data on both drives becomes lost, because the spanned volume is no longer intact.

Granted, you should always have a backup. But, the simple point being that a fusion drive increases the odds of data loss on either drive (or both drives) as the data on both drives is lost as soon as one drive or the fusion of the drives fails.

Given choices, I'd personally opt for a SSD or alternatively installing a fast 10K RPM spinner (if you can find one that is thermally compatible with the iMacs limited heat dissipation capabilities).
 

Falcon80

macrumors 6502
Original poster
Oct 27, 2012
373
94
I seem to remember there is a difference in the fusion drives, the base model having less SSD portion I think...which wasn't made clear by Apple.

I'd always go SSD, even as previously mentioned just for reliability factor...no moving parts.
Yes. The 1TB Fusion has 32 GB and 2/3 TB Fusion has 128 GB so if I am going for Fusion drive, definitely 2TB and above.
[doublepost=1496898802][/doublepost]
What about having the 2tb fusion and an external SSD for the OS and apps?

On my 27" 2011 iMac, I have a 120gb Samsung 850 evo (plugged into a TB seagate adapter) for the OS and apps. I use the internal 3tb seagate HD for the data.
Oh. Is that possible? To shift the OS to the external drive? If that is possible, then probably a 1TB fusion will be sufficient.
 

Tjmckay4

macrumors member
Apr 24, 2014
92
22
Perth, West Aus
I would avoid a fusion drive no matter what.

I would choose either a SSD or a fast spinner.
What I'm confused about is that if I have a 512gb SSD internal drive, how do I have some content on the internal SSD and some on an external SSD or HD?

I have near on 700gb in Dropbox.... How do I split my user account?? How do I back everything up?
[doublepost=1496899583][/doublepost]
Yes. The 1TB Fusion has 32 GB and 2/3 TB Fusion has 128 GB so if I am going for Fusion drive, definitely 2TB and above.
[doublepost=1496898802][/doublepost]

Oh. Is that possible? To shift the OS to the external drive? If that is possible, then probably a 1TB fusion will be sufficient.
Working on mine... don't know how that would work with the fusion drive rather than a normal HD...
 

yadmonkey

macrumors 65816
Aug 13, 2002
1,233
693
Western Spiral
I paid $500 for an SSD in my Late 2013 iMac and will never look back. Will be getting the +$200 500GB SSD in my 2017 iMac too. My thinking:

  1. Fusion or not - I don't want a hard drive in a computer that doesn't make it easy to replace. Life is too short.
  2. HDDs add a lot of heat and sometimes vibration. I hate fan noise and vibration.
  3. That mildly irritating moment when you do something in Finder and everything stalls because the HDD has to spin up.
  4. Smaller SSD capacity? Your startup volume doesn't have to be huge. Get an external drive for your music and photo libraries.
I use three external SSDs for additional storage. You can find a 512GB Crucial SSD on sale occasionally for $99.

What I'm confused about is that if I have a 512gb SSD internal drive, how do I have some content on the internal SSD and some on an external SSD or HD?

I have near on 700gb in Dropbox.... How do I split my user account?? How do I back everything up?
It's pretty easy. Tell Dropbox to use a different location and it will move the files for you. Move your iTunes or Photos library to an external and start the app holding down Option. Then direct it to the new location and everything works as it did.

As for backup, I use Backblaze for cloud backup and a local Time Machine drive. Just tell Time Machine to back up that drive in System Preferences->Time Machine->Options. Here you simply remove an external from the Exclude list.
 
Last edited:

Falcon80

macrumors 6502
Original poster
Oct 27, 2012
373
94
I paid $500 for an SSD in my Late 2013 iMac and will never look back. Will be getting the +$200 500GB SSD in my 2017 iMac too. My thinking:

  1. Fusion or not - I don't want a hard drive in a computer that doesn't make it easy to replace. Life is too short.
  2. HDDs add a lot of heat and sometimes vibration. I hate fan noise and vibration.
  3. That mildly irritating moment when you do something in Finder and everything stalls because the HDD has to spin up.
  4. Smaller SSD capacity? Your startup volume doesn't have to be huge. Get an external drive for your music and photo libraries.
Thanks for your valuable inputs! :)
 

tanwh

macrumors newbie
Jun 7, 2017
9
0
Is it possible to connect an internal 1Tb to an external 2Tb SSD via Thinderbolt 3 to merge as a bigger drive to run the OS?

Any slowness expected here?
 

jcuecker

macrumors newbie
Sep 10, 2015
25
15
Is it possible to connect an internal 1Tb to an external 2Tb SSD via Thinderbolt 3 to merge as a bigger drive to run the OS?

Any slowness expected here?
Should work fine. Thunderbolt 3 is plenty fast to run an external SSD. Even Thunderbolt 2 is fast enough.
 

gian8989

macrumors 6502
Oct 23, 2015
259
70
also running VMs for Windows and Linux.

Thanks!
Remember that if you ever want to install windows with bootcamp in the fusion drive you won't be able to use the ssd portion so the system will run only in the hdd. You probably get less nois with fusion drive than ssd+external hdd but now with thunderbolt 3 external ssd is going to be an easy option (and in 1-2 years even 2tb ssd won't cost much).
 

tanwh

macrumors newbie
Jun 7, 2017
9
0
Should work fine. Thunderbolt 3 is plenty fast to run an external SSD. Even Thunderbolt 2 is fast enough.
Realize that it is actually cheaper and probably more reliable to go for the SSD instead for the same speed and capacity.