Starting config. for 2019 iMac SSD upgrade: Fusion or SSD?

[theorist9]

I need a 27" iMac to tide myself over for a year or so. I'm thinking of buying a 2019 iMac and upgrading the SSD and RAM as needed. RAM is straightforward. But when it comes to the SSD upgrade, is it better to start with a base config that has an SSD than to start with a Fusion Drive?

Since I'm replacing the drive anyways, naively it seems better to start with Fusion Drive, since those are a few hundred dollars cheaper. However, either of these seem possible:
a) The Fusion Drive doesn't have a standard SSD (it has a "blade"). Thus it may not have a standard SSD slot, making the upgrade trickier.
b) When it comes to SSD's, the speed of the interface matters. The iMac with the Fusion drive might have a slower interface than those that come with SSD's.

Also, any recommendations on SSD upgrades (I'll be doing 1 or 2 TB)? Form what I've read, it seems to take an M.2 2280 NVMe PCIe SSD.

The OWC Aura Pro X2 is a safe choice. Are there any others that would also work well and be similarly performant? Say, something from Samsung, like what's pictured below? And is there much difference in speed between these new drives, and the ones that came stock with the machine in 2019?

 

[Sheepish-Lord]

Personally I would take a look at the iFixit website for not only their tear downs but the replacement hard drives/kits they sell as well. This might clear up any confusion you maybe have about knowing what’s inside.

 

[DeltaMac]

The Fusion drive has two devices: a spinning HDD - standard 3.5-inch size; and an NVMe blade drive.
If you replace the hard drive, you will need a 3.5 to 2.5 adapter.
You could replace the blade with a larger capacity blade. The Samsung will be a good replacement. You will need an adapter for the blade connector. The Sintech seems to work fine.

There is no difference in the logic board between Fusion and SSD-only iMacs - it just has SSD on SSD-only models, and both slots filled on Fusion configuration.

 

[theorist9]

The Fusion drive has two devices: a spinning HDD - standard 3.5-inch size; and an NVMe blade drive.
If you replace the hard drive, you will need a 3.5 to 2.5 adapter.
You could replace the blade with a larger capacity blade. The Samsung will be a good replacement. You will need an adapter for the blade connector. The Sintech seems to work fine.

There is no difference in the logic board between Fusion and SSD-only iMacs - it just has SSD on SSD-only models, and both slots filled on Fusion configuration.

I understand you're saying that the NVMe interface for the "blade" in the Fusion Drive will work identically to the NVMe interface for full SSDs in SSD-only systems, and thus a replacement SSD will perform identically in Fusion and SSD-only models.

Do I understand correctly that an adapter is needed only for the Fusion systems, and not for the SSD-only systems?

I found here that, if you upgrade a blade to an SSD, the SSD will default to operating as a stand-alone device, i.e., it will no longer be linked ("fused") to the HD, which is what I want:

https://forums.macrumors.com/threads/2019-imac-21-5-ssd-upgrade-samsung-1tb-970-evo-plus-nvme-upgrade-successful.2294156/

[It seems I alternately have the option of putting the fancy replacement SSD in the HD slot; but that's a bad idea, because the HD uses a slower interface (SATA, I'd guess). Though if you wanted, while you've got the case open, you could *also* replace the HD with a cheap SSD for faster backup storage.]

 

[DeltaMac]

The SSD blade connection on the iMac is proprietary. You need the adapter to install a non-Apple NVMe SSD. The adapter is not used when the replacement device is made for Apple (an OEM blade).
And, the Fusion configuration is a software configuration, linking the SSD with the HDD.
i "think" that an SSD-only uses an SATA SSD. The blade SSD socket is not used unless the iMac was originally set up as a Fusion drive.
But, if the Fusion drive is unlinked (which is something that you can choose to do, although the SSD part is quite small - 128GB or less ), then the iMac simply uses both drives as separate internal storage devices.
Either device can then be the boot drive, but it would be less convenient to use, compared to the Fusion configuration, which has both drives as dependent on each other (it's similar to a RAID setup, after all)
Yes, the blade slot is a much faster bus compared to the SATA bus connector.

 

[theorist9]

i "think" that an SSD-only uses an SATA SSD. The blade SSD socket is not used unless the iMac was originally set up as a Fusion drive.

Found this on fixit: "If your iMac was configured with a solid state drive or Fusion Drive, it includes a blade SSD on the back of the logic board." That would seem to indicate the auxilliary SSD on a Fusion model, and the full SSD on an SSD-only, both have the same M.2 form factor, and plug into the same PCIe NVMe interface:

iMac Intel 27" Retina 5K Display 2019 Blade SSD Replacement

If your iMac was configured with a solid state drive or Fusion Drive, it includes a blade SSD on the back of the logic board. Use this guide to...

www.ifixit.com

Given this, as you said, I'd need the adapter either way. Some are also recommending a 3 mm heat sink, because the SSD gets hot.

 

[zgagato]

I would get the fusion drive ver. and right after getting it replace the hdd with a 2tb sata SSD from samsung. 2,5" one, sata. Careful, the 870 drive doesn’t always work with macbooks, so i would try to get a 860 model. The imac is hard to take apart so its good to get something as trouble free as possible. In the long run ssd only system is the only way to go. There is also matter of replacing that tiny SSD (i think its 32 gb) with mvme SSD with an adapter. I have read here that some people were successful doing it in 2017 and 19 imacs. Sometimes there were sleep problems, but it can be corrected via terminal and pmset command. If you want to go it use samsung 970 pro or evo models. they work great in mbp retina 2015 or 17 air.

 

[rpmurray]

I believe if you get just the NVMe SSD version of the iMac it won't have the SATA cable or mounting brackets for the hard drive.

 

[Fishrrman]

The RAM on a 2019 27" iMac is easily upgradeable.

The SSD IS NOT.

It's a proprietary blade SSD, you would need some kind of adapter, and even that's not guaranteed to work.

I believe that installing it requires a COMPLETE DISASSEMBLY of the iMac -- this is not a trivial procedure, and there will be a high probability of breaking something during the process.

So...
Get one with 8gb of RAM and a 1tb internal SSD.

When the time comes for "more storage", leave the internal drive alone.
Instead, get an EXTERNAL SSD with which to supplement it.

You'll save yourself a lot of trouble by doing it this way...

 

[someoldguy]

See here .......https://forums.macrumors.com/threads/a-list-of-successful-imac-27-2012-2019-ssd-upgrades.2162435/

 

[theorist9]

The RAM on a 2019 27" iMac is easily upgradeable.

The SSD IS NOT.

It's a proprietary blade SSD, you would need some kind of adapter, and even that's not guaranteed to work.

I believe that installing it requires a COMPLETE DISASSEMBLY of the iMac -- this is not a trivial procedure, and there will be a high probability of breaking something during the process.

So...
Get one with 8gb of RAM and a 1tb internal SSD.

When the time comes for "more storage", leave the internal drive alone.
Instead, get an EXTERNAL SSD with which to supplement it.

You'll save yourself a lot of trouble by doing it this way...

Nope. It's super-easy to upgrade the SSD. Already checked before I started this thread. All I have to do is take the iMac to my local campus bookstore, which is also an authorized Apple repair center, and they'll do it for $80. No way I'm taking off that glass panel myself.

 

[theorist9]

See here .......https://forums.macrumors.com/threads/a-list-of-successful-imac-27-2012-2019-ssd-upgrades.2162435/

Yeah, I saw that before I originally posted, but I'm able to understand it much better now after the back-and-forth with this thread. It really needs some introductory text.

Also noticed that it didn't contain any of the SSD-only 2019 models.

And I'm confused why the guy from Amazon I screenshotted in my OP was able to get a 970 Evo Plus working with the Syntech adapter, even though Syntech itself says it won't work, and this is reiterated in that thread (though they might just be repeating the info. from Syntech): "It does not mater which NVMe drive you use, except the 01.2019 released Samsung 970 Evo Plus which is not compatible with any of the adapters, so do NOT use it unless a new adapter is released."

 

[Nguyen Duc Hieu]

For the iMac 2019, I would just do a new Fusion like below and be happy for a very long time:
2TB nVME blade
20TB HDD (spinning disk are great for there price vs capacity, they have 5 years warranty now)

 

[theorist9]

For the iMac 2019, I would just do a new Fusion like below and be happy for a very long time:
2TB nVME blade
20TB HDD (spinning disk are great for there price vs capacity, they have 5 years warranty now)

Whoa, it's been so long since I've looked at HDD's, I'd no idea consumer drives had gotten that big!

Given that I anticipate being able to easily fit everything I'll have on a 2 TB drive for as long as I plan to keep the machine, I don't see the benefit of using the iMac in Fusion mode. I'd think it would make more sense to maybe get a 6 TB HDD, keep it as an entirely separate drive, and use it for Time Machine backups.

As far as I can tell, it only makes sense to go Fusion if you need more storage capacity than is available on the SSD. Is there some benefit (for my use case) of Fusion that I'm not seeing here?

 

[Nguyen Duc Hieu]

As far as I can tell, it only makes sense to go Fusion if you need more storage capacity than is available on the SSD. Is there some benefit (for my use case) of Fusion that I'm not seeing here?

It's convenience, my friend.
Many people don't want to manage their files by disk volume.
That's the biggest benefit of Terabyte scale Fusion drive.

 

[theorist9]

It's convenience, my friend.
Many people don't want to manage their files by disk volume.
That's the biggest benefit of Terabyte scale Fusion drive.

Yeah, but if you're going to use the HDD portion of the Fusion drive for backup, then you need to at least create a separate partition. And according to this, if you partition your Fusion drive to use the HDD portion as a backup, MacOS turns it into a separate volume anyways: "You can use Disk Utility to add a single macOS partition to the hard disk on Fusion Drive, and that partition will function as a separate volume, not as part of Fusion Drive." So I don't see the difference between that and simply having it as a separate volume to start, i.e., not making use of the Fusion functionality at all.

About Fusion Drive, a storage option for some Mac computers - Apple Support

Fusion Drive combines the performance of Flash storage with the capacity of a hard drive.

support.apple.com

 

[Nguyen Duc Hieu]

Yeah, but if you're going to use the HDD portion of the Fusion drive for backup, then you need to at least create a separate partition. And according to this, if you partition your Fusion drive to use the HDD portion as a backup, MacOS turns it into a separate volume anyways: "You can use Disk Utility to add a single macOS partition to the hard disk on Fusion Drive, and that partition will function as a separate volume, not as part of Fusion Drive." So I don't see the difference between that and simply having it as a separate volume to start, i.e., not making use of the Fusion functionality at all.

A 20TB Fusion drive is not for back-up, my friend.
It's for fast access and instant use.
Secondary Back up is on the 100TB NAS drive, which has RAID.
Private information back-up is on the Cloud.

But, for a second thought, who need Fusion nowadays?
As we have 10GB network already, we can edit the file stored on the server.

 

[theorist9]

A 20TB Fusion drive is not for back-up, my friend.
It's for fast access and instant use.
Secondary Back up is on the 100TB NAS drive, which has RAID.
Private information back-up is on the Cloud.

But, for a second thought, who need Fusion nowadays?
As we have 10GB network already, we can edit the file stored on the server.

You didn't understand my post. If you re-read it, you'll see I was referring specifically to Fusion's applicability to my use case. And for my use case, I have < 2 TB of data total. Logically, if I install a 2 TB SSD, and have <2 TB of data, and I'm not using the HDD for backup, there is no reason to put anything on the HDD, and thus no reason for Fusion.

A 20TB Fusion drive is not for back-up, my friend.

Addressing this point specifically: If I have a 2 TB SSD, and < 2 TB data, but somehow do put some of that data onto the HDD when it's configured as part of a Fusion system, it doesn't give faster access than using the SDD by itself, it gives slower access.

 

[DeltaMac]

Part of your opinion about the fusion drive is inaccurate. The Fusion drive is a hybrid virtual volume, using both the SSD and the HDD. You don't manually choose where data is stored. Both drives are used, but neither are directly accessible by the user. The system typically operates solely from the SSD, with the speed advantage of the SSD. Apps and files also may be on the SSD, if there is enough space for that. The enormous 22TB fusion drive that was mentioned, would certainly work as a fusion drive, and the idea that large libraries could be kept on that single volume internal drive, without using external storage, is certainly an interesting idea. There would be faster retrieval of data files, even from the HDD portion of the fusion drive (compared to retrieving from an external drive, or cloud storage)
But, there also was the statement - the fusion drive is not for a backup. Files on the fusion drive would be primary storage - so you would need to come up with some external storage as part of a backup strategy.

 

[theorist9]

Part of your opinion about the fusion drive is inaccurate. The Fusion drive is a hybrid virtual volume, using both the SSD and the HDD. You don't manually choose where data is stored. Both drives are used, but neither are directly accessible by the user. The system typically operates solely from the SSD, with the speed advantage of the SSD. Apps and files also may be on the SSD, if there is enough space for that. The enormous 22TB fusion drive that was mentioned, would certainly work as a fusion drive, and the idea that large libraries could be kept on that single volume internal drive, without using external storage, is certainly an interesting idea. There would be faster retrieval of data files, even from the HDD portion of the fusion drive (compared to retrieving from an external drive, or cloud storage)
But, there also was the statement - the fusion drive is not for a backup. Files on the fusion drive would be primary storage - so you would need to come up with some external storage as part of a backup strategy.

Nope, I believe it's your understanding that's inaccurate.

Yes, I agree with your statement that "The Fusion drive is a hybrid virtual volume, using both the SSD and the HDD."

However, according to Apple themselves, the following statement is not quite accurate: "You don't manually choose where data is stored. Both drives are used, but neither are directly accessible by the user." That's the case when you have all your data in a single partition. However, according to Apple, "You can use Disk Utility to add a single macOS partition to the hard disk [emphasis mine] on [sic] Fusion Drive, and that partition will function as a separate volume, not as part of Fusion Drive." [See: https://support.apple.com/en-us/HT202574 ] So Apple is saying you can specifically put a partition on the HDD, which causes the partition to become a separate volume, even when you are using a Fusion drive. It's just that when you do that, it's no longer part of the Fusion Drive. And it's that separate volume that you could use for a backup.

My view, however, is that's unnecessarily messy. I think, if you want to use the hard disk for internal backup, it makes more sense not to combine the two drives into a Fusion drive at all: Use the SSD for your data, and use the internal HDD as a backup (not your only backup of course, but at least your first-line backup; it's necessary to have a remote backup as well, in case of fire or theft). That's what I keep saying and, for reasons that don't make sense to me, that's what others keep arguing against.

 

[DeltaMac]

Ah, OK... I should have said "Both devices are used in a fusion drive, but neither is directly accessible by the the user while configured as a fusion drive."
(While the fusion drive exists, adding a volume only applies to the HDD, not the SSD, which is why I said "not directly accessible by the user". You don't choose which device adds a partition.)
Here's how to split the Fusion drive, if you need it: https://www.lifewire.com/split-fusion-drive-apart-2260166

 

[theorist9]

Ah, OK... I should have said "Both devices are used in a fusion drive, but neither is directly accessible by the the user while configured as a fusion drive."
(While the fusion drive exists, adding a volume only applies to the HDD, not the SSD, which is why I said "not directly accessible by the user". You don't choose which device adds a partition.)
Here's how to split the Fusion drive, if you need it: https://www.lifewire.com/split-fusion-drive-apart-2260166

Yeah, it can be hard to communicate over these forums.

So do you at least agree with my bottom line: That if I've got ~ 1 TB of data, am installing a 2 TB SSD, and want to use the HDD solely as an internal backup, that there is no advantage to using the Fusion configuration. I might as well simply leave them as separate drives to start with. [As opposed to merging the two drives into Fusion after I install the new SSD, creating a partition for the backup which becomes a separate volume, which is then removed from the Fusion system.]

I also remember reading a lot of reports of problems with the Fusion drive. It seems if you don't need the added complexity from the virtualization, and its possible attendant problems, it's best to avoid it.

 

[theorist9]

Picked up the iMac today. Found it on Craig's List. 27" 2019 Core i9 with Radeon Pro 580X and 32 GB RAM. Was purchased refurbished from the Apple Store a year ago, so has AppleCare+ until 2024. Flawless condition. $1100, which I though was is a great deal compared to what these are going for on EBay (after you calculate the final price with tax and shipping).

 

[WarthogARJ]

My 2 cents on this is that while there were sme informative and useful comments made, as well as some incorrect/misleading ones (hey, it's a forrum, after all!), that the original question as asked was not really answered.
Because it was not laid out specifically.

With a 2nd-hand iMac, a LOT depends on two critical things:
- What the origina owner chose to have when they bought it
- What the next owner is willing & able to do to address those choices

For the ORIGINAL iMac, you are dealing with what APPLE was pushing due to its marketing etc model.
Like the standard model is not too high a price, but has a pretty poor selecton of components (in my outlook: maybe not yours).
So THEN, Apple says no probs, we CAN give you what you WANT.
But it's gonna cost you is whispered softly....and Apple shareholders all clap.

For the 2017 and 2019, SSD prices were still a bit high, so this hybrid fusion drive idea was sold.
A combo of (very small SSD) and a big(er) but slow HDD.
If you decided you wanted a proper full SSD at purchase, it cost you: a LOT.

And you didn't really end up with a very great choice for all that $$$ in any case.

AND, onto next stage, wen you are somene buying a used iMac.
The critical pimnt THEN is do you see a benefit in having a full SSD, and not the Fusion drive?
Again, from my perspective, if you are paying >$1,500 and maybe >$2,000 (or more) for a USED computer, I think having a Fusion drive is not such a great option.

But you THEN come to the BIGGEST advantage of buying a used iMac 27" <= 2019. That you (or somene FOR you) can UPGRADE the main components.
If you yourself don't feel you can, pay someone else.

And then, you can upgrade both the storeage as well as the CPU if you want.
RAM is easy.

It's now 2022, and big SSD's are pretty cheap.
I think most cost-effective option is to put in a (much) bigger blade/type SSD into the PCIe slot using an adaptor.
and then use it as system drive.
So that means >= 512GB.
1TB would be better.
Then since SATA 1TB and 2TB are pretty cheap now, I'd add one in the other slot.
So it means that INTERNALY you have 2-3TB of SSD.
Fast to boot and run system off.
Plus any apps that benefit from fast SSD access.
And the SATA SSD is your DAta drive.

Don't install a HDD, because it gets hot, and thermal management in an iMac is not great.
But is good idea to add the 1-2 TB Data SSD, because then you don't need to use one of the connections to run it externaly.

That's how I see it.
Alan

 

[theorist9]

My 2 cents on this is that while there were sme informative and useful comments made, as well as some incorrect/misleading ones (hey, it's a forrum, after all!), that the original question as asked was not really answered.
Because it was not laid out specifically.

With a 2nd-hand iMac, a LOT depends on two critical things:
- What the origina owner chose to have when they bought it
- What the next owner is willing & able to do to address those choices

For the ORIGINAL iMac, you are dealing with what APPLE was pushing due to its marketing etc model.
Like the standard model is not too high a price, but has a pretty poor selecton of components (in my outlook: maybe not yours).
So THEN, Apple says no probs, we CAN give you what you WANT.
But it's gonna cost you is whispered softly....and Apple shareholders all clap.

For the 2017 and 2019, SSD prices were still a bit high, so this hybrid fusion drive idea was sold.
A combo of (very small SSD) and a big(er) but slow HDD.
If you decided you wanted a proper full SSD at purchase, it cost you: a LOT.

And you didn't really end up with a very great choice for all that $$$ in any case.

AND, onto next stage, wen you are somene buying a used iMac.
The critical pimnt THEN is do you see a benefit in having a full SSD, and not the Fusion drive?
Again, from my perspective, if you are paying >$1,500 and maybe >$2,000 (or more) for a USED computer, I think having a Fusion drive is not such a great option.

But you THEN come to the BIGGEST advantage of buying a used iMac 27" <= 2019. That you (or somene FOR you) can UPGRADE the main components.
If you yourself don't feel you can, pay someone else.

And then, you can upgrade both the storeage as well as the CPU if you want.
RAM is easy.

It's now 2022, and big SSD's are pretty cheap.
I think most cost-effective option is to put in a (much) bigger blade/type SSD into the PCIe slot using an adaptor.
and then use it as system drive.
So that means >= 512GB.
1TB would be better.
Then since SATA 1TB and 2TB are pretty cheap now, I'd add one in the other slot.
So it means that INTERNALY you have 2-3TB of SSD.
Fast to boot and run system off.
Plus any apps that benefit from fast SSD access.
And the SATA SSD is your DAta drive.

Don't install a HDD, because it gets hot, and thermal management in an iMac is not great.
But is good idea to add the 1-2 TB Data SSD, because then you don't need to use one of the connections to run it externaly.

That's how I see it.
Alan

Nope, my question was laid out very specifically. You just didn't understand it. I was asking: Is there any difference between the NVMe interface on a 2019 Fusion iMac and the NVMe interface on a 2019 SSD iMac?

And one person did answer my question. So you're incorrect about that as well.

It seems the answer is a simple no, they're not different--the Fusion Drive iMac uses the same NVMe interface as an SSD-only iMac. The only difference is the Fusion iMac additionally has SATA drive.