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Buadhai

macrumors 65816
Original poster
Jan 15, 2018
1,025
400
Korat, Thailand
This is regarding a 2017 21" Retina iMac that was built with a 500GB SSD.

(More details here: https://forums.macrumors.com/thread...ating-and-undiagnosable-kernel-panics.2346159)

I took it to a shop here in Korat, Thailand, for repair. They say the SSD needs to be replaced. They originally said it was not the SSD or the RAM. Now they've backtracked and say it's the SSD.

I have some questions:
  • The Mac still panicked when I booted from an external SSD with Ventura. Could the internal SSD still cause a kernel panic even when it is not the boot drive?
  • The Mac still crashed when I booted from a Memtest86 thumb drive. Could the internal SSD still cause a crash when the Mac was booted from a Memtest86 drive "that does not require or use any operating system for execution"?
  • Is this the correct sort of SSD: NVMe – PCIe 3.1 x4?
  • Would this work: WD_BLACK SN750 SE 500GB SSD M.2 2280 PCIe Gen4 x4 NVMe
TIA
 

zgagato

macrumors member
Nov 24, 2021
59
15
Boot from another usb drive with os installed and run Drive DX software. Ot will tell you the ssd's condition.
I would pit an apple's own macbook pro retina drive from 2013 or up.
I heard from my technician that imacs can be peaky with nvme drives.
if it must be nvme use samsung 980 drive. Never had an issue in macbook pro or air 2015 -2017 models.
 

Buadhai

macrumors 65816
Original poster
Jan 15, 2018
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Korat, Thailand
Well, the machine is at the shop now in pieces, so the time for me to do more testing is over. I did boot from an external Ventura drive and ran smartctl from the command line. It found no errors on the internal SSD.

He's going to charge 7000 baht (about US$200.00) to replace the drive, but he's giving me the option to buy a drive for him to install.

I'm at a loss over what to do. If I use his drive and it doesn't stop the panicking, he'll put the old drive back and not charge me. If I buy a drive, it will be cheaper, but then I'll be stuck with it.
 
Last edited:

zgagato

macrumors member
Nov 24, 2021
59
15
The only drive that is 100% guaranteed to be working is the apple one.
If you could buy a macbook pro drive it would be ok, but again those are not new and can fail too.
Looks like you have to take risk. What kind of drive does he want to put in the imac?
 

Buadhai

macrumors 65816
Original poster
Jan 15, 2018
1,025
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Korat, Thailand
Part of the difficulty here is that he doesn’t speak English and I don’t speak Thai, so all communication has to be relayed through my wife who is a busy attorney seemingly loathe to devote much time to this. I’ve asked her to ask him what drive he’s planning to install. No answer yet.
 

Buadhai

macrumors 65816
Original poster
Jan 15, 2018
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Korat, Thailand
Well, I had a great dilemma here. The shop offered to try the WD Blue drive. If replacing the SSD didn’t cure the kernel panics then they would put the old drive back and not charge me for the new drive. Or, I could buy the drive of my choice and they’d install it. Trouble is, if the new drive didn’t fix the panics then I would have paid for a drive that I didn’t need. So, I decided it made the most money sense to let them try the WD Blue.

After reading some reviews it seems the performance difference between Black and Blue is about 15%.
 

Yebubbleman

macrumors 603
May 20, 2010
5,658
2,214
Los Angeles, CA
Those iMacs take an Apple proprietary interface for the SSD. If you want to use an NVMe drive, you'll need an adapter. I've personally always been wary of these adapters (preferring to go with OWC drives instead; though many have vouched for the exact opposite, citing poor experience, so I guess your mileage may vary?). If you are replacing the spinning drive (assuming that iMac came with one), then it's possible that there is a temperature sensor missing (not sure if 21.5" iMacs from 2012 onwards still used those in the way that 2009-2011 iMacs did). If that's the case, then your machine might be giving you grief because it keeps looking for sensor input and it's not getting any. I've seen that on way older iMacs before.
 
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Buadhai

macrumors 65816
Original poster
Jan 15, 2018
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Korat, Thailand
Turns out that this is more complicated.

The machine had been panicking since last May, but was still quite useable until last December when I took it to a Mac repair shop here in Korat, Thailand. They tried replacing the RAM, the SSD and the power supply. Nothing worked. Then they sent (I think) the logic board to a shop in Bangkok for repair. That shop was unable to repair the logic board.

So, we gave up and I went to pick it up - not repaired, no charge - yesterday.

As we were about to leave they made an offer.

They had, on hand, a 2019 iMac with a cracked screen. They offered to put our SSD, RAM and our display in the 2019 machine for 10,000 baht (about US$300). We agreed and left it there.

Well, it turns out that the 2019 machine was built with a spinning drive. So, they will try to replace that with a WD Blue SATA SSD.

Will it work? Not sure myself, but they seem confident.

I don't think the 2019 iMac needs an SSD temperature sensor, but not sure.
 

Buadhai

macrumors 65816
Original poster
Jan 15, 2018
1,025
400
Korat, Thailand

Buadhai

macrumors 65816
Original poster
Jan 15, 2018
1,025
400
Korat, Thailand
As for the original question: I found a post by a Dutch repair-shop the panic is a design flaw resulting in a problem with the orginal videocard common to the 2017 imac

I read through this again. I’m amazed. I started posting about these panics here and on other forums back in May of 2022. I got many replies suggesting a number of possible causes and diagnostic steps to try. There may have been graphics cards suggestions, but I don’t recall any.

I can’t help but wonder if this problem is so ubiquitous, as the article implies, how is it that no one seems to know about it?

BTW, none of my kernel panics had the signature of the example in the article.
 

Vesszbali

macrumors newbie
Apr 5, 2023
6
1
Good day! I want to upgrade nvme ssd in my cto imac 2017 i7-7700K with 2TB Samsung EVO or PRO... BUT donnow with 970 EVO Plus that 99.9% should work OR with 980 PRO which is PCIe 4.0. Can you all help me please to decide? (...and I'm gonna remove sata side completely) Thanks ya'll!
 
Last edited:

kschendel

macrumors 65816
Dec 9, 2014
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Assuming that the 2017 iMac understands NVMe and has a suitable m.2 slot, or available PCIe slot, then you can use any NVMe drive you like. There's no point in using a PCIe 4.0 drive, though, as it will run at PCIe 3.0 speeds, wasting your money.
 

Nguyen Duc Hieu

macrumors 68030
Jul 5, 2020
2,726
873
Ho Chi Minh City, Vietnam
Good day! I want to upgrade nvme ssd in my cto imac 2017 i7-7700K with 2TB Samsung EVO or PRO... BUT donnow with 970 EVO Plus that 99.9% should work OR with 980 PRO which is PCIe 4.0. Can you all help me please to decide? (...and I'm gonna remove sata side completely) Thanks ya'll!

If you have to ask, then you should not do it at all.
Use an external SSD drive which use nVME and USB 3.0 or thunderbolt interface.
That's the easiest thing for a common Mac user to do.
Modern Mac OS boots and runs fine from external drives.


 

Vesszbali

macrumors newbie
Apr 5, 2023
6
1
If you have to ask, then you should not do it at all.
Use an external SSD drive which use nVME and USB 3.0 or thunderbolt interface.
That's the easiest thing for a common Mac user to do.
Modern Mac OS boots and runs fine from external drives.


I will do it, don't worry. Into my previous 2015 iMac it was obvious to choose 970 Evo Plus, but my 2017 iMac maybe could run (maybe faster) with 980 PRO but not sure because of PCIe 4.0. I'm not up to date in PCIe topic and I couldn't find out which PCIe version my iMac has. That's all...
 

Vesszbali

macrumors newbie
Apr 5, 2023
6
1
Assuming that the 2017 iMac understands NVMe and has a suitable m.2 slot, or available PCIe slot, then you can use any NVMe drive you like. There's no point in using a PCIe 4.0 drive, though, as it will run at PCIe 3.0 speeds, wasting your money.
Ahh, so it has 3.0. Then yes, it's money wasting. Okkay thanks the info. So I order 970 Evo Plus right now :)
 

Nguyen Duc Hieu

macrumors 68030
Jul 5, 2020
2,726
873
Ho Chi Minh City, Vietnam
Ahh, so it has 3.0. Then yes, it's money wasting. Okkay thanks the info. So I order 970 Evo Plus right now :)

Correct me if I'm wrong, but to my understanding, no Intel-based Mac support PCIe 4.0
PCIe 4.0 is only supported from Intel CPU gen 11 and later.
The latest Mac Pro 7.1 (Xeon CPU, Casdade Lake) only support PCIe 3.0
The latest intel iMac 2020 (Intel Core i gen 10) is also the same. (PCIe 3.0)
And I don't think the M1 Mac support PCIe 4.0, either.
 

Vesszbali

macrumors newbie
Apr 5, 2023
6
1
Correct me if I'm wrong, but to my understanding, no Intel-based Mac support PCIe 4.0
PCIe 4.0 is only supported from Intel CPU gen 11 and later.
The latest Mac Pro 7.1 (Xeon CPU, Casdade Lake) only support PCIe 3.0
The latest intel iMac 2020 (Intel Core i gen 10) is also the same. (PCIe 3.0)
And I don't think the M1 Mac support PCIe 4.0, either.
Possible, I'm really not up to date in this PCIe topic.
 
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