SSD's in the fusion drives

zoran

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What capacity are the SSD drives that are contained in the 1 and 2TB fusion drives that are shipped with the iMacs?
 

nambuccaheadsau

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Oct 19, 2007
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Nambucca Heads Australia
The current 1TB Fusion has 32GB of PCI-e Blade Drive, also called SSD.

The 2/3TB Fusion in the 27" iMac has 128GB of SSD. Strongly advise you go for the 512GB pure SSD rather than a Fusion Drive. Don't forget in some countries iMacs are available from Apple refurbished.

If 512GB is not large enough, then an external USB platter drive may be the shot for movies, Photos etc.
 
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George Dawes

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Jul 17, 2014
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After my experience with FD's I'm going all SSD from now on , if I stick with macs that is

The SSD part is ok , it's the HD bit that's the problem..
 
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ncrypt

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May 16, 2012
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Would a 512GB SSD + external USB drive not perform similar to the 128GB+2TB fusion drive?

Assuming almost all data would be kept externally, surely the fusion route would be better?
 

Fishrrman

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Feb 20, 2009
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"Would a 512GB SSD + external USB drive not perform similar to the 128GB+2TB fusion drive?
Assuming almost all data would be kept externally, surely the fusion route would be better?"


NO to both questions.

Fusion is never "better".
Rather, it is (was?) a "stopgap solution" to eking more speed out of the lower-priced iMacs without putting an SSD into them.

The "fastest way" would be an iMac with an SSD inside, and then attach fast USB3 storage OUTSIDE. The external drive can be an SSD, or even an HDD. But DON'T "tie it into" the internal SSD using fusion.

Fusion can only slow an existing SSD down.
This is a 100% certainty.
 
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Guy Clark

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Nov 28, 2013
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"Would a 512GB SSD + external USB drive not perform similar to the 128GB+2TB fusion drive?
Assuming almost all data would be kept externally, surely the fusion route would be better?"


NO to both questions.

Fusion is never "better".
Rather, it is (was?) a "stopgap solution" to eking more speed out of the lower-priced iMacs without putting an SSD into them.

The "fastest way" would be an iMac with an SSD inside, and then attach fast USB3 storage OUTSIDE. The external drive can be an SSD, or even an HDD. But DON'T "tie it into" the internal SSD using fusion.

Fusion can only slow an existing SSD down.
This is a 100% certainty.
Well worth considering is a Solid State Hybrid Drive (SSHD)
https://www.seagate.com/gb/en/solutions/solid-state-hybrid/

I have Solid State Hybrid Drives in both my Late 2015 21.5" 4k iMac and Mid 2011 21.5" iMac and provide outstanding performance and unlike Fusion SSHD supports APFS.
 

zoran

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Jun 30, 2005
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Are there any downsides to the 1TB FD that are installed in the 3.4, 3.5 and 3.8GHz iMacs?
 

DeltaMac

macrumors G4
Jul 30, 2003
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One major disadvantage is the small size of the SSD in the 1 TB fusion drive, and if you have the 21.5-inch screen, the hard drive part is a 5400 rpm 2.5-inch drive.
 

padams35

macrumors 6502
Nov 10, 2016
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Are there any downsides to the 1TB FD that are installed in the 3.4, 3.5 and 3.8GHz iMacs?
1. The SSD portion is used to save the RAM state during standby mode so installing more RAM than SSD may nullify the fusion benefits. Apple recommends only using a 1TB fusion if you have 8-16GB RAM.
2. Fusion drives are limited to only two partitions.
3. The Fusing logic adds an extra layer that could break.

Otherwise a 1TB fusion on a 5K iMac should perform objectively better than any 1TB HDD.
 
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zoran

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Jun 30, 2005
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I dont think there i an option for a pure SSD!
[doublepost=1526447437][/doublepost]What does the 21-5" screen has to do with the drive, is it a matter of space?
What happens on the 27" i mac?
 

padams35

macrumors 6502
Nov 10, 2016
269
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I dont think there i an option for a pure SSD!
Macs with pure SSDs are custom build-to-order configurations usually ordered directly from Apple.

What does the 21-5" screen has to do with the drive, is it a matter of space?
What happens on the 27" i mac?
That and speed. The 21.5" has HDDs that are physically smaller and slower. The 21.5" iMac Fusion drives are SSD + 2.5" 5400rpm HDD while The 27" iMac Fusion drives are SSD + 3.5" 7200rpm HDD which are almost twice as fast.
 

gsmornot

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Sep 29, 2014
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What about 2TB Fusion that is later split into two drives? The 128GB drive plus an internal storage only drive or just add an external SSD later.
 

MSastre

macrumors 6502a
Aug 18, 2014
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I dont think there i an option for a pure SSD!
[doublepost=1526447437][/doublepost]What does the 21-5" screen has to do with the drive, is it a matter of space?
What happens on the 27" i mac?
Put your OS and apps on and external SSD drive and boot from that. Use the internal
HD for data storage.
 

zoran

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Original poster
Jun 30, 2005
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You are a doubting Thomas.

An SSD, internal or external, is up to 6X faster than the slow laptop style 5400rpm slow as molasses hard drive. An external will run at about 85-90% of the speed of the same SSD internally. Watch this for comparison:-
What i was asking is how much faster is to boot from an extSSD drive, compared to the a FD thats built in the iMac ;-)
 

gsmornot

macrumors 68040
Sep 29, 2014
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What i was asking is how much faster is to boot from an extSSD drive, compared to the a FD thats built in the iMac ;-)
If there is a difference, I suspect the FD would boot faster since its booting from an internal SSD. The issue with Fusion really is the small SSD size on most of the options compared to the larger SSD only option. My personal use makes my Fusion 2TB setup fine for me since all of my data fits easily on just the 120G SSD. I see fast boot time and fast use times. If I were using my computer for a different task maybe it would make a much bigger difference.

I have a Mac mini as well that I installed an SSD in along with the already installed 500GB spinner. I did it so I could setup Fusion. It worked great until the point Apple decided not to support APFS on Fusion and told everyone to go back to HFS+ in order to continue to update. I made the decision then to split the drives and use APFS on the SSD and use the spinner for storage. There too, with the larger SSD, I fit everything I needed on just the SSD so it was "fast", at least fast enough for most tasks and still is.
 

zoran

macrumors 68040
Original poster
Jun 30, 2005
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In that case would it be wise to install the most used apps on the SSD and the rest apps on a folder in the HD? Is that possible?
To be honest i thought that the FD drive does not separate the files by placing them either in the SSD or the HD part. I believed that files were scattered throughout all the FD and then they were used by some special way accordingly.
 

Mainbeam

macrumors member
Jun 15, 2012
39
1
Liverpool, GB
This thread has got me scratching my head now. I am looking at buying a new iMac to replace my old MBP and was going to get the 2TB FD version. It's and extra £1260 UK for a 2TB SSD. Are the FD's really that bad??
 

ignatius345

macrumors 68030
Aug 20, 2015
2,856
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But i assume that the FD is faster than a HD right?
This thread has got me scratching my head now. I am looking at buying a new iMac to replace my old MBP and was going to get the 2TB FD version. It's and extra £1260 UK for a 2TB SSD. Are the FD's really that bad??
Don't listen to the haters -- go to the Apple Store and find a Mac with a Fusion Drive and try it out yourself. They're much faster than a spinning HDD. The logic of the Fusion Drive is that it moves whatever files you use the most onto the SSD portion and runs them from there. So if you have a 2TB Fusion Drive, you have a 128 GB SSD with your most-used files on it. Your older and less-used stuff is right there too, stored on the HDD.

My iMac 5K has a Fusion drive consisting of 128GB SSD + 1TB HDD* and I really never find myself waiting significantly for anything to happen, except when I run stuff off my external USB drives, which is to be expected. And a few years ago I installed a DIY Fusion drive into my old Mac Mini (crammed in an SSD in addition to the existing HDD and used Core Storage commands to turn them into a Fusion Drive) and it was a dramatic and immediate speed increase for everything. That Mini is actually still running today and still quite fast for what it is.

People love to crap on Fusion Drives here, but for me, at the end of the day I have a big 1TB drive and in real-world usage -- graphic design work, some video and audio editing, plus regular old stuff like web and email -- it's very fast.

Of course if you can afford it obviously pure SSD is faster -- but at the prices Apple charges for the upgrade, cost gets out of hand very quickly or you'll find yourself manually shuttling stuff between the smaller SSD you can afford and whatever larger HDD you plug in for expansion storage.

* It's a 2014, from back before they started skimping on the SSD portion of 1TB FDs.
 
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