Fusion replacement options

bunger

macrumors 6502
Original poster
Mar 1, 2007
458
4
I have a 2012 27" iMac with 1TB Fusion drive and Time Machine backups.

Last night the drive failed and I am not entirely certain whether it is the HHD drive or the on-board 128GB SSD drive.

Either way, I want to ditch the Fusion config and just replace with a 1TB SSD drive.... but I have a couple of questions:

How do I disable the Fusion configuration?

What is the easiest route to do that - pull both drives and just replace the SSD drive, or just the HDD drive, or? Replacing the HDD is cheaper and slightly less difficult, but...

Will recovering from my Time Machine backup somehow try to re-enable the Fusion config?

Thanks in advance!
 

chscag

macrumors 68040
Feb 17, 2008
3,740
1,293
Fort Worth, Texas
Just pull both drives and replace it with the SSD. I'm not sure about this but you may need to use a special cable provided by OWC (Mac Sales) so that your fan does not rev up like a 747 on take off. I know that it's required if you replace the HHD combo fusion drive with a non Apple drive combo, but not sure if it's needed when replaced by a pure SSD. You can give OWC a call on their toll free line or chat line and ask. Their tech support is great.
 

bunger

macrumors 6502
Original poster
Mar 1, 2007
458
4
You can leave the original SSD. It doesn't matter.
This is amazing information - thank you for putting all of that together!

Because I am not sure which drive actually failed - IF the SSD drive failed, would it still matter if it left it in place?
 

tubeexperience

macrumors 68040
Feb 17, 2016
3,192
3,892
This is amazing information - thank you for putting all of that together!

Because I am not sure which drive actually failed - IF the SSD drive failed, would it still matter if it left it in place?
It doesn't matter.

Just make sure that you set "Startup Disk" to boot from your new SSD, so it won't boot from the other drive.
 

bunger

macrumors 6502
Original poster
Mar 1, 2007
458
4
Gotcha. So I am assuming I break the Fusion drive configuration first, replace the HDD with a SSD, then proceed as usual?
 

ZipZap

macrumors 603
Dec 14, 2007
5,513
916
Perhaps the fusion drive separated. can be fixed without opening in store.
 

Samuelsan2001

macrumors 604
Oct 24, 2013
7,694
2,121
I disabled Fusion and only the SSD is available, so I'm nearly certain the HDD has failed.
That Is most likely ssd's are pretty solid, HDD's usually last between 4and 6 years. Replace with a 1tb SATA SSD reinstate the fusion drive and have a super fast fusion.
 

bunger

macrumors 6502
Original poster
Mar 1, 2007
458
4
I am going to replace with a 1TB SSD, but I probably won't re-enable Fusion. I don't see enough benefit for that at this point...
 

EnderBeta

macrumors 6502a
Aug 5, 2016
567
521
I am going to replace with a 1TB SSD, but I probably won't re-enable Fusion. I don't see enough benefit for that at this point...
It is sort of like Raid0. You can have more speed and a higher probability that the array will fail if you combine the two drives. However if you combine them you have one larger pool of storage that manages itself.

I doubt the ssd is going to fail anytime soon. I personally would make the two ssd drives into fusion.

You should be ok for cables since you had a fusion drive to start with.
 

bunger

macrumors 6502
Original poster
Mar 1, 2007
458
4
Just wanted to update:

I broke the Fusion configuration and replaced the mechanical 1TB HDD with a Samsung Evo 850 1TB SSD drive. I did NOT re-enable Fusion; instead, the Samsung is a standalone drive and the "on-board" 128GB SDD drive is standalone.

I just ran disk read/write tests against both drives and the results were pretty consistent across multiple tests:

Samsung: 500MBs read/500MBs write
"On-Board" SSD: 300MBs read/400MBs write

I am very pleased with the performance and the test re-affirms my decision to disable Fusion given the faster speed of the new Samsung.
 
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