iMac 19,2 (6 core i7) EMC 3195 Fusion Drive Upgrade (NVMe PCIe + HHD) - T2 Chip concerns?

JShriqui wrote:

Thank you for the reply. However, there is conflicting info the OWC website "NOTE: Aura Pro X2 SSDs can only be installed in 21.5-inch iMac models that came with a factory-installed SSD or Fusion drive. Aura Pro X2 is not compatible with iMac16,1 or iMac16,2 (Late 2015), or iMac19,2 (Early 2019)." (https://ca.macsales.com/shop/ssd/owc/imac-21.5-inch/2013-2019)

I would take OWC at their word that the OWC Aura Pro X2 is incompatible with your Mac. That page is for "OWC Solid State Drives For iMac 21.5-inch (Late 2013 – 2019)" – and it shows three different lines of SSDs.

One of the SSDs lines is the Aura Pro X2 blade SSD that is incompatible with your Mac. The other two SSD lines are 2.5" SATA SSDs that would go into the 2.5" SATA drive bay where your 1 TB mechanical hard drive now lives. Those are compatible with iMac (Retina 4K, 21.5-inch, 2019) – with certain qualifications and caveats.

But also: "Note: OWC Aura Pro X2 SSDs can only be installed in 21.5-inch iMac models that came with a factory-installed SSD or Fusion drive.

This has nothing to do with the non-existent T2 chip – and everything to do with Apple being cheap. When Apple assembled some of these 21.5" iMacs, they only included a place to plug in a blade-style SSD if they needed it themselves, right away, for a factory-installed SSD or Fusion Drive. If they were shipping an iMac with just a mechanical HDD, they left off the connector you would need to plug in a blade-style SSD later.

Hard Drive (HDD) only machines can be upgraded with a OWC Mercury Extreme Pro 6G SSD or OWC Mercury Electra 6G SSD."

Because those SSDs are 2.5" SATA SSDs that go into the hard drive bay, in place of the existing mechanical drive. There are notes for the SATA SSDs that says that "OWC Mercury Extreme Pro 6G SSDs can only be installed in iMac models that came with a factory-installed HDD or Fusion drive." So quite possibly Apple was playing "leave off connectors that we don't need, right now, for ourselves" with the SATA hard drive bay, too! Buy a 21.5" iMac that only has a blade SSD, discover that there is no place to put in an internal 2.5" SATA drive (HDD or SSD) later.

My iMac is a 19,2. Hence the confusion. As described in my initial thread, the incompatibility seem to be regarding the T2 chip, which my iMac doesn't seem to have.

Nothing to do with the non-existent T2 chip, and everything to do with missing connectors.

Oh, by the way, if your Mac is not running Monterey or later yet, do not install any internal third-party drive until you have installed Monterey (or better) somewhere.

The Monterey installer reportedly checks your firmware to see if it is up-to-date. If it is not, the installer runs a firmware updater. That firmware updater checks whether your internal drive is an Apple one and will fail if you have installed a third-party SSD. That failure in turns causes the entire Monterey installation to fail. Allegedly, once your firmware is up to date, you can put in a third-party drive and install Monterey to your heart's content.

I don't know whether Ventura, Sonoma, and/or Sequoia might pull similar stunts, so IF you insist on performing surgery on the iMac, you might want to install Sequoia somewhere before putting in any third-party drive.

The safest course of action would still be to leave the internal drive alone, and get an external SSD to use as the startup drive.

Seems like for whatever reason you cannot use the OWC AuraX2 PCIe NVMe SSD in the iMac 19,2 (aka iMac 21.5" Early-2019) model. This is a specific exception to the other more generalization regarding the AuraX2 can be installed in any 21.5" iMac which original included an NVMe based SSD.

It is like saying all months have 30 days in them except February.

The OWC Mercury 6G SSDs are 2.5" SSDs which get installed where the internal Hard Drive would reside using SATA connections. This seems to be the only SSD upgrade option for your iMac. If you go with this, then go with the Extreme Pro 6G SSD (5Gb/s or 500MB/s).

FYI, the 2019 iMac is not a T2 Mac.

It would be a lot easier & less risky to just use an external USB3 or Thunderbolt3 SSD. The USB3 ports on the 2019 iMac are limited to 5Gb/s (aka 500MB/s), but the Thunderbolt 3 ports are much faster (up to 40Gb/s aka about 5GB/s shared between two ports).

ive done this to a dozen 2017-2019 iMacs -- no T2 chips on these models

2017 iMac Pro do have the T2 chip (I recall)

i use:

Sintech NGFF M.2 nVME SSD Adapter Card for Upgrade MacBook Air(2013-2016 Year) and MacBook PRO(Late 2013-2015 Year) -- the short stubby one (for more airflow around the SSD)

WD_BLACK 2TB SN850X NVMe with heatsink

Samsung 970 EVO Plus SSD NVMe M.2 also works but i've switched to the above because different current Samsung firmware throttled one SSD down after it heated up -- WD never throttled down that i've noticed

if the screw hole doesn't perfectly line up on the SSD -- carefully push it in more firmly -- when fully seated the hole lines up perfect

once you get it back together -- it plugs and plays (no complications, Erase, restore, reinstall)

I get sustained 3000MBs read/write on that configuration on all the upgrades I've done

ONE NOTE:

the 2019 i3 HDD only models don't have the NVMe slot built into the board -- they do SATA SSD upgrades only (500MBs r/w)

all 2017-2019 iMac Fusion models have the NVMe slots to do the upgrade

i am pretty if 2019 iMac shipped with SSD it also has the NVMe slot -- but I never had one disassembled to confirm

I found out the hard way about the i3 HDD only models not having the slot -- but changing the HDD with SATA SSD makes them usable...

MacTracker indicates that iMac19,2 is an iMac (Retina 4K, 21.5-inch, 2019). That is not one of the Mac computers with the Apple T2 Security Chip (Apple Support).

i read more of you posts

I would do the 32GB RAM from macsale OWC

I would pass on the used 512GB Flash blade (get the Drive Health percentages before you buy and install) -- and go with at least 1TB NVMe we were talking about -- and/or add a Samsung 970 EVO SATA SSD in place of the Fusion HDD -- use as two separate drives -- PCIe M.2 for system/apps, SATA for storage -- is how I set them up

if you elect to leave the SATA HDD in place for storage -- use DriveDX to be sure it has 90% or more Drive Health, Power On Hours are also interesting, if it is wearing out replace HDD now, I would not leave it in there if I had the iMac open

I HAVE A QUESTION:

if you open ACTIVITY MONITOR and hit Command+2

do your cores light up 12 like this, or only six?

D.I. Johnson

>>In all this discussion I note one glaring omission. Fusion drives are notoriously problematic.

what sort of problems are you talking about -- the problems i've seen on iMacs are drive failures from poor drive health resulting in corrupted systems and data -- fusion is problematic because users can't easily replace them with new drives and they spiral into defective user experience

D.I. Johnson

>>Remove the oem ssd, replace the hdd with a 6g ssd of sufficient capacity, upgrade the RAM and call it good.

first the max speed SATA SSD can deliver is around 500 MBs

the max speed of SATA HDD 5400RPM is around 80MBs

the iMac NVMe delivers sustained 3000 MBs

second if you take out the main board to remove the oem ssd (i presume you mean the original Apple flash SSD from the bottom of the main board) why would you not install a new NVMe SSD in its place and take advantage of that crazy speed?

Especially on a good 2019 i7 5K machine you want to keep in the family for a few more years

A GOOD CHEAP FIX NO LESS:

Now if you don't have the experience to remove the main board -- and don't have the budget to pay a shop $200hr for that -- simply removing the screen assembly and swapping out the SATA HDD (around 80 MBs max) with the SATA SSD (500GB max) gives you back your machine in a much-improved state

but will provide no where near the 3000 MBs speed of the MVMe (that you can upgrade 1TB SSD for around $120 parts)...

>>the i3s do not have NVMe slot

you misread --- if the i3 shipped with Fusion configuration it indeed has the NVMe slot for the upgrade

the i3 2019 iMac models that came with ONLY HDD do NOT have the slot

here is AJA test right now on a 2019 27" 5K i5 original Fusion with the Sintech/WDSN850X I noted

on Mojave -- same results on Sequoia -- same on the 21.5" i5 models

BTW

I get similar results on external Thunderbolt 3 SSD:

Enclosure: ACASIS 40Gbps M.2 NVMe SSD Enclosure, with Cooling Fan, TBU 405 Pro for M1 M2 Pro/Max, Compatible with Thunderbolt 4/3/USB3.2/3.1/3.0/2.0, M.2 Enclosure Support SSD 2280/2260/2242/2230 

SSD: WD BLACK SN850X with no heatsink (it won't fit in the enclosure)

it doesn't throttle down either like the Samsungs do when they are used externally

may go cheaper BLUE series for external, but BLACK for internal

here is the right now test on the recommended external:

(don't go with the new TB5 ACASIS enclosure unless you have TB5 hardware or you will only get 900MBs speed on TB3 and TB4 Macs)

PS:

if you have access to the 2019 NVMe slot -- do the RAM, too

these upgrades have been SEAMLESS for me hitting 4hr Blu-ray renders in FCP and hairy Photoshop work over more than a year -- no issues that I've noticed...

In all this discussion I note one glaring omission. Fusion drives are notoriously problematic.

You may want to consider forgoing the replacement of the oem ssd altogether and simplify the iMac configuration.

Remove the oem ssd, replace the hdd with a 6g ssd of sufficient capacity, upgrade the RAM and call it good.

You're welcome.

What I suggest, is to call or chat with OWC on Monday for support with their upgrade kit(s).

https://ca.macsales.com/Service/

Everything you need to upgrade the RAM, SSD's, reseal kit and install videos

are at > https://eshop.macsales.com/shop/memory/imac-2019-21.5-inch

Upgrading a T2 Mac with OWC:

1. Identify Your Mac: Determine the exact model of your Mac. 
2. Select Upgrades: Choose the components you want to upgrade (e.g., SSD, RAM). 
3. Follow OWC Instructions: OWC provides detailed instructions for installing their products, including SSDs and other hardware. 

https://eshop.macsales.com/installvideos/iMac-21-inch-2019-memory/

https://eshop.macsales.com/installvideos/imac-21-inch-2019-pciessd/

https://eshop.macsales.com/installvideos/imac-21-inch-2019-sata/

-g wrote:

what sort of problems are you talking about -- the problems i've seen on iMacs are drive failures from poor drive health resulting in corrupted systems and data -- fusion is problematic because users can't easily replace them with new drives and they spiral into defective user experience

I'm talking of exactly these problems. Fusion drives were invented to squeeze performance from a combination of slower hdd and more expensive ssd drives. Fusion drives were a kludge that is no longer needed.

The point I was trying to make was there is no reason to maintain twice the potential for problems and drive failure by leaving two drives installed.

first the max speed SATA SSD can deliver is around 500 MBs

the max speed of SATA HDD 5400RPM is around 80MBs

the iMac NVMe delivers sustained 3000 MBs

second if you take out the main board to remove the oem ssd (i presume you mean the original Apple flash SSD from the bottom of the main board) why would you not install a new NVMe SSD in its place and take advantage of that crazy speed?

Yeah, I realized my posting error too late and could no longer edit it afterward. Either option will provide better performance than the Fusion drive, and yes, the NVMe drive would be fastest.

Especially on a good 2019 i7 5K machine you want to keep in the family for a few more years

A GOOD CHEAP FIX NO LESS:

Now if you don't have the experience to remove the main board -- and don't have the budget to pay a shop $200hr for that -- simply removing the screen assembly and swapping out the SATA HDD (around 80 MBs max) with the SATA SSD (500GB max) gives you back your machine in a much-improved state

but will provide no where near the 3000 MBs speed of the MVMe (that you can upgrade 1TB SSD for around $120 parts)...

Agree!

all 12 cores should be lighting up as you do different things - if the six are in fact dead I would suspect a hardware issue you may not want to continue

you have a 6core i7 2019 with special hyperthreading (1extra core per core, 12 total) I don’t see that on i5 6core 2019 — I only see 6 on i5 models

because it’s a pain to pull the main board — if there are issues with NVMe and ram upgrades — I would be cautious installing anything but OWC ram or known good apple ram — especially installing a mystery OEM m.2 ssd

I wrote what works for me

if you never opened a 2019 iMac or pulled out its logic board — Owc has a great video on it

watch out for damaging the microphone cable … test the video cam in Photo Booth to be sure it works — and in sound> input to be sure the mic is working

and test the machine before you seal it back up

be careful not to tape over the small holes in the case for the mic or you will muffle the mic

good luck…

JShriqui wrote:

Ideally, I would like to upgrade the NVMe blade to 128 GB+, the HDD to SATA SDD, and RAM to 32 GB. I would then defuse the 2 drives (NVMe for applications, SATA SSD for Storage).

The documentation online is really confusing about upgrading the NVMe due to T2 security chip concerns. However, based on the information "Controller" and the blank result of the Terminal command, it would appear that I don't have T2 Security Chip.

So "in theory" does this mean I do a straight swap with OWC Blade type? If so, which OWC NVMe blade would be straight "plug 'n play"

Removing either the factory SSD, or the factory mechanical hard drive, will destroy the Fusion Drive and everything on it. The SSD is not a simple cache; the data is spread out across both physical drives.

So you definitely would want to make at least one bootable backup before doing anything to the internal drives.

But do you really want to open up that iMac (Retina 4K, 21.5-inch,2019)? That's going to require a pretty complete tear-down and rebuild, with a risk of damaging the machine. If you pay a repair shop to do it, it's going to cost $$$ for the labor.

I would think that if the internal drives are not actively failing, and throwing errors, a better plan would be to get an external SSD and make it your startup disk. That iMac can support

• USB-A (USB 3.0)
• USB-C (USB 3.1 Gen 2)
• Thunderbolt 3

connections to external SSDs. Although a USB-C (USB 3.1 Gen 2) SSD would not be as fast as the SSD portion of your Fusion Drive, I would think that it would be faster than your Fusion Drive, overall, by virtue of the fact that the external SSD would consist entirely of "prime real estate", while your 1 TB Fusion Drive has very little of it.