How is Monterey on an iMac with 1TB Fusion Drive

[Mac Hammer Fan]

I know Big Sur is too slow on a fusion drive with only 32GB SSD. Is this solved with Monterey?

 

[DaveFromCampbelltown]

I cannot say how it behaves with only a 32 Gb SSD, but I have a 128Gb in my iMac, and it behaves brilliantly.

Mine boots Monterey in 20 seconds, compared to 28 under Big Sur.
Most of my Apps have migrated to the SSD, except for the MS ones, and so all open in under 3 seconds.

 

[Mac Hammer Fan]

This is what I read on Apple Communities.

 

[Jay7676]

I have a fusion drive on a late 2015 mac and its extremely slow, slow to start, slow to open things

 

[ewu]

fusion is abandoned by Apple. it is too slow for Monterey, Big Sur

I use external SSD 1TB connected to usb-c port as system main disk for year in my iMac 2017.

USB 3.0 or usb-c is enough for 500MB/s.

 

[DaveFromCampbelltown]

fusion is abandoned by Apple. it is too slow for Monterey, Big Sur

I use external SSD 1TB connected to usb-c port as system main disk for year in my iMac 2017.

USB 3.0 or usb-c is enough for 500MB/s.

My late 2015 27" iMac, with 128Gb +2Tb Fusion is extremely fast, for both Big Sur and Monterey.
It boots Big Sur in 24 seconds and Monterey in 16. Word typically starts up the first time after booting in under 5 seconds. LibreOffice and Pages are similarly fast.

As well, not only have Apple not abandoned Fusion Drives, they have made it much easier to build your own. It used to be a two-stage process, which involved copying the long Volume ID, but now it is a simple command --

diskutil apfs create [drive1] [drive2] [FusionDriveName]

The system sorts out which is the SSD and which is the HDD and assigns them automatically.
It works so well, you can partner a good SSD with a slow USB 2 HDD and still get impressive results.

 

[Jay7676]

I have the basic 1TB fusion drive that came with my mac and I seem to be one of the only people with an extremely slow system. Mine takes about 3 minutes to start and then a further 4 minutes to open Apple mail or Chrome and then at least 30 seconds or more for every app I want to open.

Not sure what else I can do, I have tried clean my mac etc and disabled a load of things running at start up.

Strangely when I got the Mac last year and it had High Sierra I think it flew along, Big Sur slowed startup and now Monterey is almost killing it.

Strangely most of the slow downs started after I installed Photoshop but I have disabled Creative cloud and stopped all the adobe services but still the same issue

 

[vvv7]

5-10 minutes to start Big Sur with no/yes open all apps. 1TB Fusion with 32 GB ssd inside, iMac 27 2017. Planning switch to 2TB nvme (worry re sleep and other potential issues).

 

[gilby101]

Not sure what else I can do,

But an external SSD and use that as macOS boot disk.

 

[linuxophile2]

I know Big Sur is too slow on a fusion drive with only 32GB SSD. Is this solved with Monterey?

Well, I tried to install and it hosed. It now claims disk full when finder states 76 GB free. Then I tried installing on an external ssd connected via usb c and it hosed that too. I am desperately trying to downgrade. Apparently Monterey misbehaves with external drives connected via usb machine is an iMac 2017.

strangely it installed without ptoblems on a mini 2014

 

[SketchyClown]

My late 2015 27" iMac, with 128Gb +2Tb Fusion is extremely fast, for both Big Sur and Monterey.
It boots Big Sur in 24 seconds and Monterey in 16. Word typically starts up the first time after booting in under 5 seconds. LibreOffice and Pages are similarly fast.

As well, not only have Apple not abandoned Fusion Drives, they have made it much easier to build your own. It used to be a two-stage process, which involved copying the long Volume ID, but now it is a simple command --

diskutil apfs create [drive1] [drive2] [FusionDriveName]

The system sorts out which is the SSD and which is the HDD and assigns them automatically.
It works so well, you can partner a good SSD with a slow USB 2 HDD and still get impressive results.

It's even simpler than that.

diskutil apfs resetFusion

I replaced the 1TB spinner in my Late 2015 iMac with a 1TB SATA SSD. Executing that command in Terminal when setting up macOS will reset the Fusion Drive setup. It auto detects which drive is the PCI SSD and uses it for the primary "faster" drive and uses the SATA drive for "secondary" duties.

The system is very responsive and boots quickly compared to the stock Fusion drive which was "beachball" central.

Blackmagic reports around 700MB/s writes and 1800MB/s read. Not exactly blazing, but better than a stock Fusion setup.

 

[DaveFromCampbelltown]

diskutil apfs resetFusion

I replaced the 1TB spinner in my Late 2015 iMac with a 1TB SATA SSD. Executing that command in Terminal when setting up macOS will reset the Fusion Drive setup. It auto detects which drive is the PCI SSD and uses it for the primary "faster" drive and uses the SATA drive for "secondary" duties.

The system is very responsive and boots quickly compared to the stock Fusion drive which was "beachball" central.

Blackmagic reports around 700MB/s writes and 1800MB/s read. Not exactly blazing, but better than a stock Fusion setup.

The instruction I gave was to create a Fusion drive from a pair of external drives, i.e. a SSD and a HDD. Yours, which really should be

diskutil resetFusion

no need for the apfs, is for rebuilding an internal drive pair into a Fusion drive.

However the usual bottleneck is the CPU, rather than Fusion drive speeds. I find that booting up from an external SSD/HDD Fusion drive, loading apps and performing operations is little different from my internal Fusion drive.

There are times that diskutil won't recognise which of the external drives is the SSD and which is the HDD. In that case I have used --

diskutil apfs createContainer -main [SSDVolume] -secondary [HDDVolume]
diskutil apfs addVolume [fusiondrivevolume (eg drive8)] APFS [FusionDriveName]

There is lots more to the APFS commands, but this will do to get a volume for installing a copy of macOS.

Note I said SSDVolume, not SSDDrive. You can split the SSD and HDD into two or more volumes and assemble the fusion drive from one of each volume. This way I have been able to get two Fusion drives out of each pair of SSD/HDD.

Note also that the SSD speed really overrides the HDD speed. I was able to make a perfectly functioning Fusion drive from a USB 3 SSD and a USB 2 HDD. If you have an old slow drive, you can get great performance from it by adding it into a Fusion drive. The only time you notice it is when the SSD is full and all writes go directly to the HDD.

However, one of the magic things about a Fusion drive is that it tries to keep several Gbytes free on the SSD so any writes happen to it, and then they are moved to the HDD when it's not busy.

 

[SketchyClown]

Yes the command was incorrect. Good catch.

diskutil resetFusion is the proper command.