A list of successful iMac 27" (2012-2019) SSD upgrades

[Terraaustralis]

Hi Tristan,
Regarding Samsung 980 Pro NVME, I ran simple tests three months ago against the WD SN770. Both PCIE 4.0 running on a PCIE 3.0 iMac 2019 6 core. I published results on tonymacx86 and the response from far better informed people than myself confirmed the Samsung 980 Pro is not suitable. The drive ran well with good Black Magic score but still trim times accumulate whether used as a boot drive internally or externally.

The WD SN770 is in a class of its own for economy and speed. To quote one user:

“The SN770 is the lowest cost way to max out speeds on an older PCIe Gen 3 motherboard. Highly recommended. No Sata based SSD, which costs nearly the same per GB, comes close to this performance.”

And: https://www.tomshardware.com/reviews/wd-black-sn770-ssd-review

I sent my Samsung back to Amazon.

 

[theorist9]

Hi Theorist,
I am not an expert but a couple of comments regarding Monterey and WD Black may help:
I have recently upgraded an iMac 19.1 with a WD770 which is regarded as a ‘safe’ NVME for Mac. I was running Monterey without problems but as Apple upgrades were installed so odd glitches appeared; mainly bluetooth but also a slowing in boot times.

For the benefit of others in the household, I use Sony MX1000 headphones while watching movies. Getting the bluetooth to sync was slow in Monterey 12 but became impossible to connect in later versions so I moved to Ventura which was fine.

If you research Monterey performance my problems where mild by comparison with many others. See how your system behaves moving to Ventura.

Regarding the SN850, it is an expensive blade for a PCIE 3.0 system. Others may correct me, but I do not believe it is yet on the ‘safe’ list of Macrumors NVME SSD. The kernal panic is usually a sign of hardware/firmware incompatibility.

“WD Black NVMe SSD v1, v2 and v3, WD Blue SN550 (FW Update mandatory), SN750, SN750 SE” This comment on Macrumours suggests you may have a firmware upgrade task ahead of you.

I hope this helps solve your problems.

Cheers

Hi Terraaustralis. Thanks for your comments.

I suspect the issue has more to do with the Monterey upgrade than the WD S850. Oddly, the problems I've experienced seem to be specifically associated with trying to run bus-powered USB 3.2 Gen 2 SSD's (Kingston XS2000's) from the USB-A ports. I switched to driving them with my Thunderbolt ports, and all the issues I reported have disappeared.*

Further, there are three other members on this thread who have installed the SN850 into their iMacs (@oKUtItyp, @MBehr2, and @genexx), and none have reported issues.

In case you're curious I am why I chose to use a fast PCIe 4.0 SSD in a PCIe 3.0 interface, there were two reasons:

1) 4 x PCIe 3.0 is indeed limited to 4000 MB/s. While that doesn't allow me to take advantage of the SN850's max sequential R/W speeds (7000/5300 MB/s), what's most important for boot drive performance are the random reads and writes which, even for the SN850, are far below the 4000 MB/s PCI 3.0 ceiling. I.e., that ceiling only limits the SN850's performance for large sequential reads & writes. It doesn't limit its performance for smaller sequential reads and writes, and for any random operations. And I figured the SN850 would have significantly better performance in those more critical categories than an older aftermarket PCIe 3.0 SSD.

2) Futher, I get better performance even for large sequential reads and writes than a PCI 3.0 SSD provides. That's because none of the latter come close to the 4000 MB/s ceiling. The WD SN850 doesn't hit it either, but at least it comes closer. While I don't have a direct 2 TB to 2 TB comparision, this is how the SN850 compared to the stock Apple SSD:

*It is mysterious that plugging SSD's into USB-A ports should create global OS and internal drive issues that would seem to have nothing to do with the USB ports. But, after the last Monterey update, the drives did start spontaneously disconnecting when attached to those ports—and one reason drives could disconnect is because they are drawing more power than then the ports can (or are allowed to) supply. So I suppose it is at least possible that the Monterey update affected that power setting, and it is further plausible that something that causes a port power limit to be exceeded could have global effects on the PCIe system (which feeds the internal drive as well) (but of course I am purely speculating here). [Drive disconnection was a widely reported issue with an earlier Monterey update, I think to 12.2; but I wasn't on Monterey then, so I didn't experience this myself.]

[I also had disconnection issues with a SanDisk Extreme USB 3.2 Gen 2 SSD even when attached to a TB port, so my guess is that drive draws so much power that it was exceeding even the TB port's limit. That's why I returned it and switched to the Kingston XS2000's, even though they are slower.]

 

[Terraaustralis]

Hi everyone,
After a failure of the fusion drive, I'm currently working on an upgrade, unsuccessful for now.

I saw no trace of the samsung 980 in the thread, and am testing it. So far, no success with the 980 on my imac 17.1. The imac boots, but the SSD is invisible in DU. Same with a 970EvoPlus 500GB I had lying around.
The SSDs are both confirmed working (in usb>nvme adapters), and the formatting makes no difference.

Some caveats, and potential points of failure :
- I made a quick spreadsheet based on the first post compilation (if you have better, welcome!), and it seems the 17.1 imac shows a pattern of "partial successes", and no complete success. No trace from the 970evoplus or 980 there (except the post previous to the one before mine).
- I am using (three different) "small" nvme adapters, with tape.
- I have been unable to update the SSD firmware with Samsung Magician (which doesn't see SSDs when on my usb adapter).


My next attempts would be
0 - any 'software' suggestion without buying new hardware ?
1 - sourcing a NGFF2013 Sintech card
2 - sourcing and trying a samsung 970 (€€ attempt)
3 - sourcing and trying a WD Black (€€€ attempt)

Any hints regarding scenario 0 ?

ATTEMPTED UPGRADE tristan:
Device: iMac 17.1
Blade upgrade: 128GB Apple -> Samsung (980 or 970evoplus)
Speed test: not yet available
OS: not yet relevant?
FileSystem: not yet relevant?
Boot Rom Version: 522.0.0
Location: Belgium
Issues: No SSD detected

View attachment 2321214

Hi Terraaustralis. Thanks for your comments.

I suspect the issue has more to do with the Monterey upgrade than the WD S850. Oddly, the problems I've experienced seem to be specifically associated with trying to run bus-powered USB 3.2 Gen 2 SSD's (Kingston XS2000's) from the USB-A ports. I switched to driving them with my Thunderbolt ports, and all the issues I reported have disappeared.*

Further, there are three other members on this thread who have installed the SN850 into their iMacs (@oKUtItyp, @MBehr2, and @genexx), and none have reported issues.

In case you're curious I am why I chose to use a fast PCIe 4.0 SSD in a PCIe 3.0 interface, there were two reasons:

1) 4 x PCIe 3.0 is indeed limited to 4000 MB/s. While that doesn't allow me to take advantage of the SN850's max sequential R/W speeds (7000/5300 MB/s), what's most important for boot drive performance are the random reads and writes which, even for the SN850, are far below the 4000 MB/s PCI 3.0 ceiling. I.e., that ceiling only limits the SN850's performance for large sequential reads & writes. It doesn't limit its performance for smaller sequential reads and writes, and for any random operations. And I figured the SN850 would have significantly better performance in those more critical categories than an older aftermarket PCIe 3.0 SSD.

2) Futher, I get better performance even for large sequential reads and writes than a PCI 3.0 SSD provides. That's because none of the latter come close to the 4000 MB/s ceiling. The WD SN850 doesn't hit it either, but at least it comes closer. While I don't have a direct 2 TB to 2 TB comparision, this is how the SN850 compared to the stock Apple SSD:

View attachment 2321958


*It is mysterious that plugging SSD's into USB-A ports should create global OS and internal drive issues that would seem to have nothing to do with the USB ports. But, after the last Monterey update, the drives did start spontaneously disconnecting when attached to those ports—and one reason drives could disconnect is because they are drawing more power than then the ports can (or are allowed to) supply. So I suppose it is at least possible that the Monterey update affected that power setting, and it is further plausible that something that causes a port power limit to be exceeded could have global effects on the PCIe system (which feeds the internal drive as well) (but of course I am purely speculating here). [Drive disconnection was a widely reported issue with an earlier Monterey update, I think to 12.2; but I wasn't on Monterey then, so I didn't experience this myself.]

[I also had disconnection issues with a SanDisk Extreme USB 3.2 Gen 2 SSD even when attached to a TB port, so my guess is that drive draws so much power that it was exceeding even the TB port's limit. That's why I returned it and switched to the Kingston XS2000's, even though they are slower.]

Cannot argue with your choice of NVMe Theorist.

Power draw may be a factor with simultaneous use of several externals but would not so easily explain drop out from a single drive - if that happens? You can calculate power draw needed by NVMe and externals and see how it stacks up against port specs. Blaming Monterey seems doubtful as others would have the same problem and I have not noticed reports of that nature. I once upgraded a GPU on a G4 which drew more power than the computer could sustain. No Kernal panic, just cut out and closed down. Does not match your symptoms.

This excerpt from Superuser indicates that overloading power draw drops out individual USB devices according to a pre-determined sequence.

What is the maximum power supplied by a USB 3.0 port?

USB 3.0 specifies 900mA (0.9A) per port. What happens when you plug a non-powered (no AC adapter) hub into an USB 3.0 port? Do all of the items plugged into the port need to use 900mA maximum total

superuser.com

These figures may also help you:

TB3 ports typically have a power output limit of 15W. Consequently, hubs connected to these ports cannot supply more than 15W to peripherals unless they have an external power source too.


The power output by a USB-C port on a device is referred to as "bus power". Here's a brief summary of the power output for different port types:

USB-A (2.0, 3.0) ports usually output 5W (5V at 1A).

• USB-C ports typically output either 7.5W (5V at 1.5A) or 15W (5V at 3A).
• Thunderbolt 3 ports generally output 15W (5V at 3A).
• USB-C ports implementing USB-PD 3.0 can receive up to 100W (20V at 5A).
• USB-C ports implementing USB-PD 3.1 can receive up to 240W (48V at 5A)

Or Again:
You have to differ between the maximum current a port can output in reality and the maximum current as it is defined by the USB standard. In reality, most USB ports can output more current than the standard defines but a standard-compliant device will not draw more power than the standard allows.
According to the USB standard the following limits apply:

• USB-A port 2.0: 0.5A
• USB-A port 3.0 (now called USB 3.1/3.2 Gen 1): 0.9A
• USB-C port without Power Delivery (PD): 1.5 A or 3.0 A (the maximum current if negotiated between port, device and cable.

Still think you should try upgrade to Ventura and see how your system behaves. It will determine whether behaviour is OS based or not. I find Ventura very stable on my iMac 19.1 but my attached devices are few.

Cheers

 

[theorist9]

This excerpt from Superuser indicates that overloading power draw drops out individual USB devices according to a pre-determined sequence.

What is the maximum power supplied by a USB 3.0 port?

USB 3.0 specifies 900mA (0.9A) per port. What happens when you plug a non-powered (no AC adapter) hub into an USB 3.0 port? Do all of the items plugged into the port need to use 900mA maximum total

superuser.com

These figures may also help you:

TB3 ports typically have a power output limit of 15W. Consequently, hubs connected to these ports cannot supply more than 15W to peripherals unless they have an external power source too.


The power output by a USB-C port on a device is referred to as "bus power". Here's a brief summary of the power output for different port types:

USB-A (2.0, 3.0) ports usually output 5W (5V at 1A).

• USB-C ports typically output either 7.5W (5V at 1.5A) or 15W (5V at 3A).
• Thunderbolt 3 ports generally output 15W (5V at 3A).
• USB-C ports implementing USB-PD 3.0 can receive up to 100W (20V at 5A).
• USB-C ports implementing USB-PD 3.1 can receive up to 240W (48V at 5A)

Or Again:
You have to differ between the maximum current a port can output in reality and the maximum current as it is defined by the USB standard. In reality, most USB ports can output more current than the standard defines but a standard-compliant device will not draw more power than the standard allows.
According to the USB standard the following limits apply:

• USB-A port 2.0: 0.5A
• USB-A port 3.0 (now called USB 3.1/3.2 Gen 1): 0.9A
• USB-C port without Power Delivery (PD): 1.5 A or 3.0 A (the maximum current if negotiated between port, device and cable.

Yes, I was having that issue even with a single XS2000 attached to the USB-A ports. It's not clear to me from that post whether the USB 3.0 limit of 4.5 W (900 mA at 5 V) is per port or per bus. FWIW, Anandtech measured 4.74W peak power consumption when a 2 TB XS2000 is connected to a TB port (I have both 2 TB and 4 TB models), though the device should adjust downward when connected to a USB 3 port.

Blaming Monterey seems doubtful as others would have the same problem and I have not noticed reports of that nature.

I think you're overly discounting the Monterey update as a possible cause.

First, how do you explain that the only change precipitating these issues was upgrading to Monterey 12.7.1? For a year prior to this, I had zero disconnection issues with these drives. Perhaps others haven't reported this issue with this upgrade, but few others have exactly the configuration I have.

Second, there have been numerous reports of exactly this issue across multiple versions of Monterey, with different people reporting having issues with different versions, so is it that surprising that I'm experiencing this with this specific version?

Third, this article reports that "this can happen randomly or after a recent macOS update". Note that it's not referring to a specific OS update; rather it is saying simply the act of updating can change things in a way that precipates this, which is exactly what I'm experiencing:

Fix External Hard Drive Keeps Disconnecting on Mac[Updated]

Why does your external hard drive keeps disconnecting on Mac? Fix the external hard drive or USB drive that keeps disconnecting on Ventura/Monterey/Big Sur/Catalina.

iboysoft.com

Still think you should try upgrade to Ventura and see how your system behaves. It will determine whether behaviour is OS based or not. I find Ventura very stable on my iMac 19.1 but my attached devices are few.

I previously tested Ventura on a separate partition, and the colors seemed off, so I decided to stick with Monterey. I read somewhere Ventura might have a color bug that interferes with certain calibrations.

Plus Monterey is working for me now that I've moved my drives to TB ports, so why risk rocking the boat by switching to Ventura, which also has known drive disconnection issues? Yes, you haven't experienced them, but others have.

If I do bother to upgrade, I'll instead test out Sonoma (I'll need to upgrade to it eventually, so upgrading to Ventura now and Sonoma later would be double work) and, if it works well, I'll wipe everything and do a clean install. I haven't done a clean install in a long time, which has left me with lots of old files, and it's time to clean out the cruft.

 

[Terraaustralis]

OK Fair comment, I am glad the issue is settled by using TB and you have a working solution. I am no lover of Monterey and the evidence you provide re. Monterey is persuasive, but your symptoms and those of the iBoysoft article differ markedly. No mention of freezes and kernal panic in the article, only disconnection and re-connection.

It would also be nice to eliminate coincidence re Monterey upgrade. Without wishing to make a mountain out of the topic, it seems to me that other avenues should not be excluded. Several points are unclear and a kernal panic suggests a possible hardware incompatibility somewhere. Excessive power draw is less convincing to me as the industry standards address such issues before a product goes on the market. I acknowledge exceptions can occur.
Let me ask:

1. During the stable year prior to Monterey upgrade, were you using SN850 NVMe? I think not.
2. You mentioned three Macrumors users with SN850’s, were those NVMe’s in the identical iMac model you are using? As I think you know, what works in one iMac model does not necessarily work in another.
3. You have a powerful i9 iMac which is built to deliver all the power you need for drives you describe. A single SX2000 would not ordinarily be a problem. That it has been, suggests to me possible hardware issues.
4. Did you try all the remedies listed in the iBoysoft article?

Since there is a lot of work in following through all implied hardware isolation tasks, I can understand you putting the matter aside while all works well with TB.

By unhappy coincidence today, the WD SN770 NVMe which I installed three months ago and worked faultlessly, is now suddenly suspect as I cannot boot up the NVMe internal drive without a kernal panic. I am runing off the other internal Samsung Sata SSD. I have made no changes externally or internally whatsoever. My point is that compatibility is time based. These machines are very sensitive. Further, OS upgrades are increasingly complex piles of software which tend to invite new difficulties as they are introduced. Therefore, like yourself, once an OS is stable, I stick with what works and avoid upgrading.

As I have mentioned, your problem sounds more like a hardware issue to me and I would be interested to learn what happens, if and when you upgrade to Sonoma. I hope it all goes away for you. If problems recur, please send a post.

Cheers.

 

[theorist9]

1. During the stable year prior to Monterey upgrade, were you using SN850 NVMe? I think not.

"I think not."?? Note that the installation date of my SN850 is something about which you have no information whatsoever, so it's simply bizarre that you feel free to make such a strong assertion about it. And not surprisingly, your assertion is incorrect.

The fact is that I purchased this machine used, knowing the 500 GB drive would be too small, and that I would need to first upgrade to 2 TB before putting it to use. Thus other than some initial comparative testing with the OEM drive, I've never used this machine other than with the SN850 NVMe. Upgrading to that drive was the first thing I arranged after purchase. I bought the machine in mid-May 2022, had my local Apple service center install the SN850 the following week, and posted about it here on May 30, 2022:

https://forums.macrumors.com/threads/a-list-of-successful-imac-27-2012-2019-ssd-upgrades.2162435/page-39?post=31134473#post-31134473

I've been using Monterey since the beginning. As I got the machine in May 2022, I started with Monterey 12.4, then upgraded regularly as updates were released.

I added the two XS2000's in Sept 2022, so I've been using these for over a year without issue until the upgrade from Monterey 12.7 to 12.7.1.

2. You mentioned three Macrumors users with SN850’s, were those NVMe’s in the identical iMac model you are using? As I think you know, what works in one iMac model does not necessarily work in another.

me: 2019 27" i9 iMac
MBehr2: 2019 27" i9 iMac
oKUtItyp: 2017 27" i5 iMac
genexx: unspecified

As for oKUtItyp's 2017 result: If a recently-released SSD (like the SN850) works in an older iMac, it's very likely it will work in a newer iMac as well. All the model-dependent incompatibiities (that I recall) involve a recently-released SSD working in a later-model Mac but not in and older one, not the other way around. This makes sense. The SN850 was released in 2021. It would be strange for it to work in a 2017 iMac but not in a 2019 iMac.

3. You have a powerful i9 iMac which is built to deliver all the power you need for drives you describe. A single SX2000 would not ordinarily be a problem. That it has been, suggests to me possible hardware issues.

It's not about the overall power of the machine, it's about what's going on with these specific ports.

4. Did you try all the remedies listed in the iBoysoft article?

I tried some of them, along with others they didn't mention. The one I can't try is this: "Disable or uninstall third-party anti-virus programs." That's because such programs are required to access my university's VPN.

Here is what I did try:
PRAM reset
SMC reset
Boot into Safe Mode (can help by clearing certain caches)
Reinstall MacOS
Wipe and reformat external drives.

As I have mentioned, your problem sounds more like a hardware issue to me.

I don't believe it is simply hardware. I think it is a very complex hardware-software interaction involving those USB ports, the attached drives, my OS, and my machine's specific software configuration, since the behavior is determined entirely by the ports to which those external SSD's are connected, and the behavior manifested itself immediately after the OS upgrade.

I would be interested to learn what happens, if and when you upgrade to Sonoma. I hope it all goes away for you. If problems recur, please send a post.

Will do. I usually like to wait until about x.4 to update, to give Apple and the app developers time to work through most of the inevitable early-release bugs. But maybe I'll be adventurous and update earlier!

 

[Terraaustralis]

Hi Theorist,
I am not an expert but a couple of comments regarding Monterey and WD Black may help:
I have recently upgraded an iMac 19.1 with a WD770 which is regarded as a ‘safe’ NVME for Mac. I was running Monterey without problems but as Apple upgrades were installed so odd glitches appeared; mainly bluetooth but also a slowing in boot times.

For the benefit of others in the household, I use Sony MX1000 headphones while watching movies. Getting the bluetooth to sync was slow in Monterey 12 but became impossible to connect in later versions so I moved to Ventura which was fine.

If you research Monterey performance my problems where mild by comparison with many others. See how your system behaves moving to Ventura.

Regarding the SN850, it is an expensive blade for a PCIE 3.0 system. Others may correct me, but I do not believe it is yet on the ‘safe’ list of Macrumors NVME SSD. The kernal panic is usually a sign of hardware/firmware incompatibility.

“WD Black NVMe SSD v1, v2 and v3, WD Blue SN550 (FW Update mandatory), SN750, SN750 SE” This comment on Macrumours suggests you may have a firmware upgrade task ahead of you.

I hope this helps solve your problems.

Cheers,

 

[Terraaustralis]

This was your original question:

I upgraded my 2019 27" iMac with a 2 TB Western Digital SN850 SSD connected via a Sintech NGFF M.2 nVME SSD adapter card. It was installed by an Apple authorized service center.

I'm wondering if there is an incompatibility between my aftermarket SSD and/or adapter card, and Monterey 12.7.1 specifically.

With no dates given, this reads as a recent event. OK, so I was wrong about the date of SN850 upgrade. Lets just wait and see what the future brings.

 

[theorist9]

This was your original question:

I upgraded my 2019 27" iMac with a 2 TB Western Digital SN850 SSD connected via a Sintech NGFF M.2 nVME SSD adapter card. It was installed by an Apple authorized service center.

I'm wondering if there is an incompatibility between my aftermarket SSD and/or adapter card, and Monterey 12.7.1 specifically.

With no dates given, this reads as a recent event. OK, so I was wrong about the date of SN850 upgrade. Lets just wait and see what the future brings.

I can see how you misread it, but the entire starting quote was actually this, indicating the new event about which I was posting was the Monterey 12.7.1 update, not the drive installation. Thus what you quoted misrepresents my question, by omitting the first and most important sentence:

Anyone having issues after the Monterey 12.7.1 update?

I upgraded my 2019 27" iMac with a 2 TB Western Digital SN850 SSD connected via a Sintech NGFF M.2 nVME SSD adapter card. It was installed by an Apple authorized service center.

I'm wondering if there is an incompatibility between my aftermarket SSD and/or adapter card, and Monterey 12.7.1 specifically.

[Or maybe it has nothing to do with that [referring to the SSD]—owners of 2019 MBPs (which can only have stock Apple SSDs) had this issue with an earlier Monterey update; they said the fix was to exclude the Bootcamp partition from Spotlight Indexing. I don't have Bootcamp, but I do have two other partitions, which I just excluded. So maybe that will fix things.
https://www.reddit.com/r/techsupport/comments/wkffu5 ]

Starting with that update, I've been getting daily cursor freezes, forcing a reboot. Never experienced that before...

[bolded emphasis added]

I also included a link to my post about the SSD installation, which includes the date, but I understand people often don't bother checking those:

Details on my upgrade:

https://forums.macrumors.com/threads/a-list-of-successful-imac-27-2012-2019-ssd-upgrades.2162435/page-39?post=31134473#post-31134473

And agreed, let's wait and see what the future brings.

 

[Terraaustralis]

Need help with my iMac 27" 5K 2019. I installed a WD SN850X. I put everything back together and saw that one of the LEDs lighted up when I plugged in the power. However, when I press the power button, the computer won't turn on. Did I break something or forget a reconnect a part? Does anyone have any ideas about what might be the problem? Much appreciated.

First impression is you have damaged your power unit and will have to replace it.

It may be your power unit is not properly plugged into the logic board.

LED 1 = power connected.
LED 2 = power board active
LED 3 = CPU and mother board functioning. CPU and GPU connected.
LED 4 = Logic board and LCD panel connected. Video signal generated.
LED 5 = Logic board, LCD panel, video generated, video generated, LCD panel turns on backlight.

If you test your iMac before closing you should get the first three LED showing.

As you saw only one I reckon it was the first LED which confirms only power connection.

Turning to details: Did you:

Wear surgical gloves, wear a static electricity grounding strap or use bare hands? I have blown a power board with the merest brush of a bare hand. The capacitors on the power board are very sensitive to static electricity and you have to remove the power board to access the Motherboard and NVme in 2019 iMac. I always wear surgical gloves. I see guys on You Tube upgrading NVMe with bare hands and cringe.

Metal tools also should be earthed before you use them. They simply need to touch earthed iron or steel. In a domestic situation that is less possible. Touching the steel block of a desktop PC power unit is sometimes possible. I am forced to rely on the frame of the Aluminium iMac which is not a good conductor or the magnets in older models. So I am careful to keep tools in contact with screws only and use plastic spudgers.

Until you take your computer to an authorised dealer you will not know how extensive the damage is. A used power unit may be purchased for around US$150 but a Motherboard is in the $1000 area from Macfixit or Apple.

I hope my observation is wrong. Recheck every step alongside the Macfixit video’s visible on another computer if possible, but based on what you say, buying another used 2019 iMac is the best solution and migrate the HDD.

Best Wishes

 

[tristan_praxis]

Hi Tristan,
Regarding Samsung 980 Pro NVME, I ran simple tests three months ago against the WD SN770. Both PCIE 4.0 running on a PCIE 3.0 iMac 2019 6 core. I published results on tonymacx86 and the response from far better informed people than myself confirmed the Samsung 980 Pro is not suitable. The drive ran well with good Black Magic score but still trim times accumulate whether used as a boot drive internally or externally.

The WD SN770 is in a class of its own for economy and speed. To quote one user:

“The SN770 is the lowest cost way to max out speeds on an older PCIe Gen 3 motherboard. Highly recommended. No Sata based SSD, which costs nearly the same per GB, comes close to this performance.”

And: https://www.tomshardware.com/reviews/wd-black-sn770-ssd-review

I sent my Samsung back to Amazon.

Thanks for your answer Terraaustralis,

I bought and tried the WD SN770 this morning and it appears that it is not readable on my imac 17.1 (late 2015). Nor did the Samsung980, nor does the Samsung EVO970plus.
I could read the WD SN770 on an enclosure on a recent mac.

At this point I just look for something that'll work (not necessarily that'll work the fastest).
I am longing for a "conclusive" chronological listing compatibilities and non-compatibilities with different drives. At this point, the main variable seems to be the imac's chipset compatibility with evolving types of SSDs, with a pivot to a new chipset after the 17.1 generation ?

From afar, it would look like I'd have to go back in time to buy older SSDs, or skim the second hand market. I'm at my third unsuccessful SSD though, it becomes costly.

 

[Terraaustralis]

boot

Thanks for your answer Terraaustralis,

I bought and tried the WD SN770 this morning and it appears that it is not readable on my imac 17.1 (late 2015). Nor did the Samsung980, nor does the Samsung EVO970plus.
I could read the WD SN770 on an enclosure on a recent mac.

At this point I just look for something that'll work (not necessarily that'll work the fastest).
I am longing for a "conclusive" chronological listing compatibilities and non-compatibilities with different drives. At this point, the main variable seems to be the imac's chipset compatibility with evolving types of SSDs, with a pivot to a new chipset after the 17.1 generation ?

From afar, it would look like I'd have to go back in time to buy older SSDs, or skim the second hand market. I'm at my third unsuccessful SSD though, it becomes costly.

Go to page 1 in this forum and research from the dozens of reports what works on your iMac.
You will find the answers if you search.

 

[Terraaustralis]

Please Help with Sintech NGFF NVMe adapter problem.

I recently upgraded my 2019 iMac NVMe with a WD SN770 using a Sintech NGFF adapter as recommended in these posts. After working flawlessly, booting from the NVMe for 3 months, last Tuesday I booted up and was greeted by a Kernal Panic. I reseated the NVMe but on re-assembly, booting from the blade continues to cause Kernal Panic.

It has been pointed out to me by trs96 on tonymacx86.com that the Long Sintech NGff adapter does not support PM981, 950 Pro, WD Blue NVMe, or SN570 /SN770

My question to all using the WD SN770 is; which adapter are you using? I need to replace my Sintech.

 

[Terraaustralis]

Installation Date: August 2023

Device: 2019 iMac 6 core i5 (Intel 9600K) Coffee Lake, model 19.1 MRR12LL/A A2115 EMC 3194
Original Blade: Apple 256GB SSD
Upgraded Blade: 2TB WD Black SN770
HDD upgrade: 2tb SATA Samsung 870 Evo
Speed test: Read:3053MB/s, Write: 2965MB/s
Adapter: Sintech NGFF 2013-2017 macbook
NVMe Heatsink: Copper/Graphene Ali Express No Brand

Successful Upgrade

Process Notes:
NVME options.
I tested 2TBSamsung 980 Pro Gen 4.0, 2TB Adata SX 8600 Gen 3.1 and 2TB WD Black SN770 Gen 4.0
Adata was incompatible; Samsung worked well but reliable advice indicated I would get problems later:
WD Black ran silky smooth with performance close to Samsung. Screen still taped on pending resolution of adapter problem.
No temperature sensor on SATA. Macs Fan Control excellent. Temperature range 38° - 45°. Average load.

Update: December 2023
Booting from SN770 results in Kernal Panic. No obvious reason but advice received indicates Sintech incompatible with the SN770.
Solution awaiting.
Am booting from Samsung in the meantime.

 

[Betgo]

This probably the wrong way to add a new post but this is my first time so please point me in the right direction if it is the case:
My story so far I have a:
iMac 17.1 late 2015 27". i5, 3.3 GHz, A1419, EMC2834 it came with a fusion drive made up from a 2TB HDD with 128G apple blade and 8G of memory. I had issues (random shut downs software not working very slow etc.) I tried first aid but eventually everything stopped and I had no option but to format which took me back to the original OS all data was lost by this point not such a disaster but it was a pain.
Moving on I was led to believe by apple the HDD was my issue so i changed the HDD for a Samsung SSD 870Evo 1TB, at this point I didn't fully understand the 'Fusion' bit so I formatted and installed OS Monterey on the new SSD the mac was clearly still sick (very slow but not shutting down) so after reading here and other sites i decided to change the blade SSD which i did for a Timetec 500GB I had also installed 32GB of memory at some point. This process has taken some deveral weeks but the iMac is funcioning well (I think).
Still not fully understanding the Fusion bit I formatted the blade SSD and reformatted the Evo SSD so i had what I thought to be 500GB for the boot drive and 1TB of storage but that was not the case all was working on the blade SSD. Then finaly the epiphiny; i got my head aroung the fusion bit and fused the Evo and the blade now i have the one drive showing a 1,51TB MacintoshHD which is of course all SSD.
This leads me to my question; now that i have a mac which is working i think well (ihave the blackmagic speed thest which I dont fully understan but I think it shows me around 1500MB/s write and 1600MB/s read) I read that the fusion is not so good. Could somebody try and explain please?

 

[tristan_praxis]

Go to page 1 in this forum and research from the dozens of reports what works on your iMac.
You will find the answers if you search.

I had done so, but the lack of "unsucessful upgrades", and the increasing lack of "older" NVMEs on the market made me hope that recent NVMEs had not yet been tested, and might work. Older NVMES are increasingly out of stock, and there are likely thousands of imac17.1s around worthy of an upgrade.

UPDATE : I have succeeded upgrading a 17.1 imac with SS970evo, SS980, WDSN770 black without any issues (sleep/boot) at all for 5+ reboots/sleeps. Will document and rewrite current post.

For context: I've been mounting/dismounting an imac 27" (Bootrom 522.0.0.0.0) about 30 times in a week, testing 4 different SSDs and 3 different adapters, without getting a single recognized SSD in recovery mode.
Then I realised why it went wrong. I was entering online recovery mode every time. I tried booting from a bootable USB drive w/ Monterey and BAM, everything worked smooth as butter.

While I'm very happy, I have to rethink all my speculations. Here's my new spreadsheet

As strange as it seems to be, according to the post in 1, I would have the first successful upgrades with a SS980 and WDSN770. To be confirmed over the next weeks.

• I would suggest to include "Boot and install from a fresh external USB/TB drive for best results" in the first post ! (I don't feel like being in the authority position to do it myself)
• I would suggest to include warnings about well known platform-independent issues with some SSDs, for example the Samsung ones. I am hesitant to pursue working on a SS970EVO upgrade after reading about this drive.
• I would suggest to further nuance what "successful" means, perhaps by including "mileage" of upgrades (3 reboots ? a week's use ? 1 year of use ? etc.) .

I would gladly pursue the documentation of nonworking attempts, but I have not encountered one yet !

My updated 'successful upgrades"

Device: late 2015 17.1
Original Blade: Apple 128GB SSD
Upgraded Blade: 1TB WD Black SN770, 1TB SS970, 1TB SS980 - all three successfully tested
HDD upgrade: similar disk (seagate 2tb)
Speed test: not yet done, but systems run smooth as butter
Adapter: three different small ones
NVMe Heatsink: currently shopping for one


I needed a clearer story, and this is what I came up with. I have redrawn a simplified table of compatibility between imac models and NVME models. It takes into account most of the upgrades mentioned in the thread + my own experiences and failures (and from others). The imacs and the NVME are chronologically ordered (approx date of release). It highlighted some patterns:
- A compatible upgrade for ALL imacs is the Samsung 970 EVO (not plus ! not pro!). Intel 660 is a good candidate too.
- Don't try SSDs sold on the market on 17.1 imacs or older versions. There is little hope. This is important : From end of 2023 on, you will likely not be able to upgrade a 17.1 with a default purchasing approach.
- There are no documented flawless upgrades of the 17.1 imac. You'll have to disable sleep.



This approach would perhaps need some doublechecking and completion, but it seems to me that it synthesises the 52+ pages of this thread at this point. Most of the debates have to do with attempts that escape those patterns.

I cannot stress enough how important it is to document nonworking cases in a shared inquiry. The absence of documented nonworking attempts made me trust a scattershot approach, while we are on a minefield instead.

 

[Betgo]

Thank you Tristan for your response though not entirely sure i fully understand. If you are asking for more detail on the upgrade then i used in order of installation as follows:

Timetec 32 Go KIT (4x8 Go)Compatible pour Apple Late 2015 iMac (27'' avec écran Retina 5K) DDR3L 1867MHz/1866MHz PC3L-14900 2Rx8 CL13 1.35V 204 Pin SODIMM Memory Module MAC RAM Upgrade pour iMac 17,1​

​

SSD Samsung 870 EVO 1To

​

Timetec Mac SSD NVMe PCIe Gen3x4 3D NAND TLC Lecture jusqu'à 2000 Mo/s Compatible avec Apple MacBook Air (2013-2015,2017), MacBook Pro (2013-2015),iMac(2013-2019),Mac Pro (2013), Mac Mini (512GB)​

The iMac is working without any issues.
Was that your question?

 

[tristan_praxis]

Thank you Tristan for your response though not entirely sure i fully understand. If you are asking for more detail on the upgrade then i used in order of installation as follows:

Timetec 32 Go KIT (4x8 Go)Compatible pour Apple Late 2015 iMac (27'' avec écran Retina 5K) DDR3L 1867MHz/1866MHz PC3L-14900 2Rx8 CL13 1.35V 204 Pin SODIMM Memory Module MAC RAM Upgrade pour iMac 17,1​

​

SSD Samsung 870 EVO 1To

​

Timetec Mac SSD NVMe PCIe Gen3x4 3D NAND TLC Lecture jusqu'à 2000 Mo/s Compatible avec Apple MacBook Air (2013-2015,2017), MacBook Pro (2013-2015),iMac(2013-2019),Mac Pro (2013), Mac Mini (512GB)​

The iMac is working without any issues.
Was that your question?

I was answering to TerraAustralis.

But seeing your post, I can provide a brief answer :
avoid using the "fusion" mode ; it was designed for a time when SSDs were expensive and small, and has its own issues, in short : if one of the physical drives of your fusion drive fails, the data of both drives of your entire fusion drive is lost. A fusion drive multipies the risk of data loss by 2. I'd avise to keep your 2 drives as separate partitions, use your on-board SSD for OS and fast storage, and use your secondary drive for slower storage. A common approach is to use a large onboard SSD for everything, and a internal SATA connected HDD for live, permanent TimeMachine Backups of that onboard SSD.

 

[Betgo]

Ok thanks so if i understand correctly I should split the fusion then use the blade "on board" ssd for the os i understand this bit but partitions are a bit like fusion, was, a mystery to me. For this to work maybe i needed a bigger blade drive but I will give your advise a try once i understand partitioning.

 

[Terraaustralis]

I had done so, but the lack of "unsucessful upgrades", and the increasing lack of "older" NVMEs on the market made me hope that recent NVMEs had not yet been tested, and might work. Older NVMES are increasingly out of stock, and there are likely thousands of imac17.1s around worthy of an upgrade.

I needed a clearer story, and this is what I came up with. I have redrawn a simplified table of compatibility between imac models and NVME models. It takes into account most of the upgrades mentioned in the thread + my own experiences and failures (and from others). The imacs and the NVME are chronologically ordered (approx date of release). It highlights some patterns:
- A compatible upgrade for ALL imacs is the Samsung 970 EVO (not plus ! not pro!). Intel 660 is a good candidate too.
- Don't try SSDs sold on the market on 17.1 imacs or older versions. There is little hope. This is important : From end of 2023 on, you will likely not be able to upgrade a 17.1 with a default purchasing approach.
- There are no documented flawless upgrades of the 17.1 imac. You'll have to disable sleep.

This approach would perhaps need some doublechecking and completion, but it seems to me that it synthesises the 52+ pages of this thread at this point. Most of the debates have to do with attempts that escape those patterns.

I cannot stress enough how important it is to document nonworking cases in a shared inquiry. The absence of documented nonworking attempts made me trust a scattershot approach, while we are on a minefield instead.


View attachment 2322749

Fair comment tristan-praxis.
Prior to my own attempt to upgrade a 2019 iMac I too concluded the Samsung 970 was a safe choice. Unfortunately, though I searched assiduously, I could not find one to purchase. Finally I tested the Samsung 980 Pro which ran and performed well but received comment indicated problems would emerge

I had done so, but the lack of "unsucessful upgrades", and the increasing lack of "older" NVMEs on the market made me hope that recent NVMEs had not yet been tested, and might work. Older NVMES are increasingly out of stock, and there are likely thousands of imac17.1s around worthy of an upgrade.

I needed a clearer story, and this is what I came up with. I have redrawn a simplified table of compatibility between imac models and NVME models. It takes into account most of the upgrades mentioned in the thread + my own experiences and failures (and from others). The imacs and the NVME are chronologically ordered (approx date of release). It highlights some patterns:
- A compatible upgrade for ALL imacs is the Samsung 970 EVO (not plus ! not pro!). Intel 660 is a good candidate too.
- Don't try SSDs sold on the market on 17.1 imacs or older versions. There is little hope. This is important : From end of 2023 on, you will likely not be able to upgrade a 17.1 with a default purchasing approach.
- There are no documented flawless upgrades of the 17.1 imac. You'll have to disable sleep.

This approach would perhaps need some doublechecking and completion, but it seems to me that it synthesises the 52+ pages of this thread at this point. Most of the debates have to do with attempts that escape those patterns.

I cannot stress enough how important it is to document nonworking cases in a shared inquiry. The absence of documented nonworking attempts made me trust a scattershot approach, while we are on a minefield instead.


View attachment 2322749

 

[Terraaustralis]

Following on from your chart, this post may be of interest as is this chart of Samsung drives which lead to problems with trim/boot times:

Choosing a Compatible NVMe SSD for your macOS Boot Drive

Introduction to NVMe Choices If you have any previous hackintosh experience, you'll know that a limited number of hardware components have native support in macOS. You can't buy just any graphics card and expect it to work. Only certain Broadcom models of Wifi/BT cards have native support etc...

www.tonymacx86.com

also: https://www.tonymacx86.com/threads/update-pcie-4-samsung-980-pro-v-pcie-4-wd-black-sn770.326792/

From OS 12 upward Samsung is not recommended and WD Black is proven safe.

One problem I have discovered, newer WD Black SN850x and SN770 are not compatible with recommended Sintech adapter. I am seeking help from SN770 users in identifying which adapters work best with these new WD Black NVMe SSD’s

Putting that aside, your comment re 2017 iMac is helpful and should be much appreciated as it saves a lot of research for those to whom it applies.

As for the list of failures, my SN770 qualifies until I can find a compatible PCIe adapter!

 

[iMac2019]

Hi,
FYI, I've used this adapter from aliexpress (the long one) + kapton tape (x2) without no hi-cup untill now; but the upgrade is relatively recent.
I watch over potential trim time issue without any noticeable performance deterioration so far.
WD_BLUE SN570 1TB Blade was detected and trim activated with no manual intervention.
It could have been plug and play without the fastidious process of dismantling the machine, something I want to avoid to do again, at all costs.

Carte adaptateur SSD M Key M.2 NGFF PCIe AHCI, pour Bella BOOK Air 2013 2014 2015 2017 A1465 A1466 Pro A1398 A1502 A1419 2230-2280 SSD M2 - AliExpress 7

Smarter Shopping, Better Living! Aliexpress.com

fr.aliexpress.com

A pic from an ali buyer -> https://ae01.alicdn.com/kf/A9becc1f1121f46e08d656bc069bf17bcm.jpg

No issue after fresh macOS 12.7.1 install and restore with Assistant Migration.

 

[Terraaustralis]

Hi,
FYI, I've used this adapter from aliexpress (the long one) + kapton tape (x2) without no hi-cup untill now; but the upgrade is relatively recent.
I watch over potential trim time issue without any noticeable performance deterioration so far.
WD_BLUE SN570 1TB Blade was detected and trim activated with no manual intervention.
It could have been plug and play without the fastidious process of dismantling the machine, something I want to avoid to do again, at all costs.

Carte adaptateur SSD M Key M.2 NGFF PCIe AHCI, pour Bella BOOK Air 2013 2014 2015 2017 A1465 A1466 Pro A1398 A1502 A1419 2230-2280 SSD M2 - AliExpress 7

Smarter Shopping, Better Living! Aliexpress.com

fr.aliexpress.com

A pic from an ali buyer -> https://ae01.alicdn.com/kf/A9becc1f1121f46e08d656bc069bf17bcm.jpg

No issue after fresh macOS 12.7.1 install and restore with Assistant Migration.

Thank you for your response. Link is appreciated.

It is silly how these Chinese product are retailed unbranded. I have a similar adapter purchased from a different dealer and will test it out. I can only identify the product by the number printed black on black, how helpful is that? It appears the same manufacture and is sold all over Ali Express. It took three months for the fault to arise with my long Sintech. Time testing is yet another hurdle.

I shall let you know what happens. Thanks again.

 

[iMac2019]

You're right, Time testing is yet another battle.

These are the same or very similar products, sold by hundreds of different vendors.

So, I bet your problem doesn't lie with the adapter, which is mainly a passive PCB with just reconfigured tracks.

The only cause could be poor-quality / bad welded connectors or imperfect physical adjustment of the inserted blade / mecanical stress.

Boring enough, the only way to know the root cause is to swap with an other blade / an other adapter, if the machine works stably after booting from an external drive.

a valuable tool I use for experiment / validation testing -> https://www.amazon.fr/dp/B08Z7DK7CF

Wish you to be lucky.

 

[Terraaustralis]

Thank you for your tip and sentiments.

According to WD, it is the adapter which is incompatible. However the NVMe enclosure you suggest also does not show compatibility with SN770.

That may or may not be a result of timing. Being a Dramless NVMe,the SN770 has a different design to those NVMe with on-board RAM.

Extract:
For Western Digital: WD Blue SN550 / WD-Black SN750 / WD-Black SN850 / WD Blue 3D NAND SATA SSD M.2 2280 / WD-Black SN750 / WD-Black SN850 / WD Blue 3D NAND SATA SSD M.2 2280 /

The search continues!