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I'm confused and need some guidance. I have a 21-inch 2019 iMac A2116 MRT42 with an Apple Fusion Drive that seems to be running slow. I'm planning to upgrade to an NVMe SSD using an adapter. I'm looking for recommendations on the best brand and model to use to avoid any compatibility issues. Some friends have mentioned that their systems have experienced panics after using the NVMe SN770 or other WD models for a few months. Please provide me with a recommendation for an NVMe upgrade. Speed and model are not that important to me. My main goal is to have a seamless experience using the adapter and not have any problems after a few months.

Has anyone used this Lexar SN620 nvme model? Do you think it's compatible with a 2019 iMac?
 
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Hi, I wonder if
* for iMac 27" late 2013, A1419, EMC 2639 which was ordered that time with one single internal mass storage - the 500GB blade SSD, latter one still working as boot, system drive and as a storage of lot of user stuff (however not every user stuff).
* the standard power and SATA cables* will work same well as cable/adapter this kind but intended for iMac 27 late 2013 (either branded by Apple or some 3rd party)

*) in mind those cables offered and purchased for computers running under Windows/Linux and other class devices with the use of SATA storage; connectors fitting in the main concern.

iMac should receive coming months two major hardware upgrades (CPU + blade SSD) + optionally one minor upgrade (SATA SSD, 2.5 inch). Mentioned SATA SSD will be this iMac's very first drive populated to its 3.5 inch bay and is planned to be used only for storage of user data. I guess in case presented above the iMac has neither mounting brackets nor the cabling inside, so both are to be purchased if one plans to conduct mentioned upgrade. Any experiences in this matter?

Secondary question, will every 2.5 inch to 3.5 inch adapter frame be suitable for the use in this case? I mean the location of mounting screws; maybe some other points matter here too.

By the way, me was luck to find this iMac A... and EMC number. However several tutorials, and hardware component offers use for Mac-family devices the numbers starting with M. What kind of number are these and how to find it for own iMac?

Update, Apr. 27th
Well, Apple-original SATA+Power-cable found in regional market of used spare parts at good price and of good condition physically. This way no needs exist any more to look for other cable builds.
Regarding mounting brackets: those taken from iMacs of which other build years will fit 27 inch late 2013 well?
Do the 2.5 inch form-factor SSDs attach to iMac Apple original SATA+Power cable in same direct way (no additional adapter) as those drives populated to iMac 27 late 2013 by Apple? As of time being I consider the use of form-factor adapter 2.5 to 3.5 inch which is free of electrical connectors - just converting the physical size 2.5 to 3.5 and attaching the new SSD (2.5 inch) directly to Apple-original SATA+Power cable.
 
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Blade + HDD upgrade

Device: iMac19,2 2019 – 21.5” - MRT42LL/A (3Ghz i5-8500, Fusion HDD+32GB blade)
Blade upgrade: 32GB Blade -> 500GB Lexar nm610 (up to 2100MB/s Read & up to 1600MB/s Write)
HDD upgrade: 1TB SATA Apple HDD -> 180GB SSD Intel pro
Adapter: Chinese model
Speed test
: 1400 MB/s read, 700 MB/s write (Blackmagic Disk Speed Test)

Issues after fresh OS install: The write speed of this Blade SSD randomly fluctuates between 30MB/s and 700MB/s for no apparent reason. This erratic behavior makes the overall SSD read/write performance slower than expected

Does anyone have a solution for this erratic SSD write speed?

I'm looking for a low-risk upgrade option, and I'm considering the Samsung 970 EVO. Is it a good and reliable choice for long-term performance?
 
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Blade + HDD upgrade

Device: iMac19,2 2019 – 21.5” - MRT42LL/A (3Ghz i5-8500, Fusion HDD+32GB blade)
Blade upgrade: 32GB Blade -> 500GB Lexar nm610 (up to 2100MB/s Read & up to 1600MB/s Write)
HDD upgrade: 1TB SATA Apple HDD -> 180GB SSD Intel pro
Adapter: Chinese model
Speed test
: 1400 MB/s read, 700 MB/s write (Blackmagic Disk Speed Test)

Issues after fresh OS install: The write speed of this Blade SSD randomly fluctuates between 30MB/s and 700MB/s for no apparent reason. This erratic behavior makes the overall SSD read/write performance slower than expected

Does anyone have a solution for this erratic SSD write speed?

I'm looking for a low-risk upgrade option, and I'm considering the Samsung 970 EVO. Is it a good and reliable choice for long-term performance?
That seems to be an issue with that specific SSD model. Also on Reddit there are reports of the same behaviour like you experienced, with no solution except to look for another drive. The Samsung 970 Evo seems like a reliable drive for the iMac, but I'd suggest collecting a bit more (recent) feedback as my last iMac update is almost 2 years back...

Good luck!
 
That seems to be an issue with that specific SSD model. Also on Reddit there are reports of the same behaviour like you experienced, with no solution except to look for another drive. The Samsung 970 Evo seems like a reliable drive for the iMac, but I'd suggest collecting a bit more (recent) feedback as my last iMac update is almost 2 years back...

Good luck!

Thanks for your reply. Do both the 970 evo and 970 evo Plus models work well on the iMac 2019? Are there any performance differences between them on the device, and which one is more recommended?

I did some more research and found on Reddit that some users have reported issues with the 970 EVO (or Evo Plus) trimming with iMac 2019, and that it can sometimes take up to 5 minutes to boot up!!
I'm even more confused now. I'm probably going to have to go with the WD , but I've also heard of panic boot issues with some of their models, like the sn770!! What about the sn750 or sn550? Are there any issues with those?
 
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That seems to be an issue with that specific SSD model. Also on Reddit there are reports of the same behaviour like you experienced, with no solution except to look for another drive. The Samsung 970 Evo seems like a reliable drive for the iMac, but I'd suggest collecting a bit more (recent) feedback as my last iMac update is almost 2 years back...

Good luck!


Thanks for your reply. Do both the 970 evo and 970 evo Plus models work well on the iMac 2019? Are there any performance differences between them on the device, and which one is more recommended?

I did some more research and found on Reddit that some users have reported issues with the 970 EVO (or Evo Plus) trimming with iMac 2019, and that it can sometimes take up to 5 minutes to boot up!!
I'm even more confused now. I'm probably going to have to go with the WD , but I've also heard of panic boot issues with some of their models, like the sn770!! What about the sn750 or sn550? Are there any issues with those?
 
Blade SSD upgrade

Device:
iMac15,1 2014 – 27”
Blade upgrade: 128GB Blade -> 2TB WD SN850X
Adapter: Chinese model
Speed test
: 850 MB/s read, 800 MB/s write
 
This is how I gonna to populate the iMac 27 late 2013 with its first SATA 2.5 inch SSD - this way convinces me. For this presentation only spinning HDD as SDD still not purchased - I am currently on tracking the price fluctuations and waiting for free time window to open iMac and conduct upgrades.
Frame own SATA+power adapter removed for reduction of plugged connections count, which is always good. I don't see any need to have additional data and power adapters. It should work according to my experience with HDDs/SDDs in USB-docks and if to consider that SSD will be standard drive, the drive used to be installed in PCs.
All materials already in possesion were ordered from regional reterials at acceptable price.

For blade upgrade the OWC Aura Pro X2 waits on shelf for installation - purchased last 5 weeks from regional retailer which seems to have huge portfolio of computer components in its offer. Retailer has in my estimation a good chance to have big customer base - how well their inventory may fluctuate. How are the odds the Pro X2 to have the latest available firmware version flashed already?
 

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Hi guys, I'm new here.. can't seem to find how to post a new thread but found this thread so thought you guys may be able to help, or at least direct me to the right direction. I'm trying to use OCLP to upgrade my iMac, but can't get it to work.. its an iMac 27-inch Late 2013 (Intel i5 3.4Ghz Quad-Core, 16GB RAM DDR3, NVIDIA GTX 775M 2GB, Samsung SSD 860 EVO 500GB. I tired it with all OS versions, from Ventura all the way to the latest Sonoma but it just gets stuck and then restarts to a black screen or to a folder symbol with a question mark on it with a URL below (support.apple.com/mac/startup). I looked online as well and can't find anyone with similar issue... any ideas?
 
I am fixing my Mum’s late 2015 iMac 27” with Fusion Drive. The blade SSD has failed and I’ve just finished removing it from the machine, as its presence was causing lockups. Now the machine is working again, but only has a lowly spinning HDD.

I am trying to decide whether to go the NVMe or SATA route for a replacement SSD. NVMe seems preferable on the surface as it’s faster and would also allow me to keep the stock HDD for additional file storage. However, reading through these comments it seems there are two main issues, firstly that the late 2015 iMac has sleep issues with NVMe drives and also that TRIM/garbage collection does not always work correctly resulting in reduced performance including slow startups. However, a lot of people have also reported no issues, so I’m not quite sure what to think.

Is there a particular brand or model of NVMe SSD that is suited to the late 2015 iMac? The one I’m looking at currently on Amazon is a WD SN770.

Perhaps it would be better to just go the SATA route to avoid these potential issues? And if I do, am I also correct in thinking that the temperature sensor that OWC sells for this model is also not needed?

Edit: I've read through the whole 56 pages of the thread and now understand the situation a lot better. It seems that since Big Sur/Monterey were released, wake from sleep issues have been 98% resolved for the iMac 17,1 (late 2015). Also, the Samsung NVMe drives are probably best avoided, as people seem to have been reporting more issues with them than with other brands. The TRIM issues and slowdown do seem to crop up for some people so I'll just have to see how I go but hopefully it won't be a problem.
 
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Right, I decided to go ahead and order a WD SN770, along with a couple of different NVMe adapters. I'll report back on how things go once I've fitted it.
 
Blade + HDD upgrade

Device: iMac19,2 2019 – 21.5” - MRT42LL/A (3Ghz i5-8500, Fusion HDD+32GB blade)
Blade upgrade: 32GB Blade -> 500GB Lexar nm610 (up to 2100MB/s Read & up to 1600MB/s Write)
HDD upgrade: 1TB SATA Apple HDD -> 180GB SSD Intel pro
Adapter: Chinese model
Speed test
: 1400 MB/s read, 700 MB/s write (Blackmagic Disk Speed Test)

Issues after fresh OS install: The write speed of this Blade SSD randomly fluctuates between 30MB/s and 700MB/s for no apparent reason. This erratic behavior makes the overall SSD read/write performance slower than expected

Does anyone have a solution for this erratic SSD write speed?

I'm looking for a low-risk upgrade option, and I'm considering the Samsung 970 EVO. Is it a good and reliable choice for long-term performance?
Try the Crucial P3 Plus 4TB model with a Sintech NGFF M.2 nVME SSD Adapter. I have a 2019 iMac 27'' with a Crucial blade for almost year and I've never had any issues. Apple used Crucial/Micron RAM and Drives on many older iMacs, I believe, so expect compatibility.
 
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I've done the upgrade, adding in a 2TB Blade SSD and retaining the 2TB spinning HDD. I changed the BR2032 battery while I was in there, too. :cool:

As mentioned above, my POS 128GB Apple blade SSD had failed, effectively bricking the machine until it was removed.

Device: Late 2015 - 17,1 - MK482LL/A (3.3GHz i5-6600, Fusion HDD+128GB blade)
Blade upgrade: 128GB Blade -> 2TB WD Black SN770 NVMe SSD
Speed test: 2770 MB/s read, 2640 MB/s write
OS: Monterey 12.7.5
Location: London, UK
Adapter: Sintech ST-NGFF2013
Issues after fresh OS install: Absolutely none, the upgrade works like a champ. I put the machine to sleep a few times and it wakes up normally.


IMG_8570.JPG
 
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Is it by sheer coincidence that standard M.2 drives are shorter than Apple SSDs by exactly the right amount to incorporate an adapter?
 
Is it by sheer coincidence that standard M.2 drives are shorter than Apple SSDs by exactly the right amount to incorporate an adapter?
TBH, I first wanted to post a cheeky reply (à la 'funny that the adapter has exactly the size so one could fit an M.2 drive into an Apple') but in hindsight - that is indeed a revelation - imagine the other way round!
 
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TBH, I first wanted to post a cheeky reply (à la 'funny that the adapter has exactly the size so one could fit an M.2 drive into an Apple') but in hindsight - that is indeed a revelation - imagine the other way round!
We must enjoy this while we can. The next generation of iMacs we tinker with will have everything soldered on. I expect to have perfected my BGA rework skills by that time.
 
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I'm pontificating jumping down this rabbit hole. Before I waste my time though, I'm currently booting from an external drive in an Orico Thunderbolt 3 enclosure and getting 1300/2300 write and read speeds from Blackmagic. Am I likely to notice a significant upgrade in performance? iMac 27" 2019, 19.1. It's a minefield of what to buy although I'm fairly confident with disassembly and reassembly.
 
Try the Crucial P3 Plus 4TB model with a Sintech NGFF M.2 nVME SSD Adapter. I have a 2019 iMac 27'' with a Crucial blade for almost year and I've never had any issues. Apple used Crucial/Micron RAM and Drives on many older iMacs, I believe, so expect compatibility.
Thanks for your reply. Some people have also had the same experience with the sn570 on the 2019 iMac and said it works without any issues. I will probably use the same sn570 as well
 
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OK. Decided to go for it, ordered so far WD SN770, ST-NGFF2013, cutting tool, adhesive, screen suction cups. To order, caddy and SSD. Any suggestions? iMac 27" 19,1.
 
I'm pontificating jumping down this rabbit hole. Before I waste my time though, I'm currently booting from an external drive in an Orico Thunderbolt 3 enclosure and getting 1300/2300 write and read speeds from Blackmagic. Am I likely to notice a significant upgrade in performance? iMac 27" 2019, 19.1. It's a minefield of what to buy although I'm fairly confident with disassembly and reassembly.
Those are already good speeds, I bet you wouldn't notice the difference.
 
Device: iMac19,2 2019 – 21.5” - MRT42LL/A (3Ghz i5-8500, Fusion HDD+32GB blade)
Blade upgrade: 32GB Blade -> WD BLUE SN570 500GB
Adapter: Chinese model
Speed test
: 3100 MB/s read, 2200 MB/s write (Blackmagic Disk Speed Test)

Issues after fresh OS install:
The writing speed drops from 2200 MB to 300 MB after a few seconds or the next test. The SSD temperature rises to an average of over 50 degrees Celsius during this time. Again, after a few minutes of retesting, the speed starts at 2200 MB and then drops back to 300 MB after the next test or a few seconds later. Can someone help and give suggestions on how to fix this problem?
 
Device: iMac19,2 2019 – 21.5” - MRT42LL/A (3Ghz i5-8500, Fusion HDD+32GB blade)
Blade upgrade: 32GB Blade -> WD BLUE SN570 500GB
Adapter: Chinese model
Speed test
: 3100 MB/s read, 2200 MB/s write (Blackmagic Disk Speed Test)

Issues after fresh OS install:
The writing speed drops from 2200 MB to 300 MB after a few seconds or the next test. The SSD temperature rises to an average of over 50 degrees Celsius during this time. Again, after a few minutes of retesting, the speed starts at 2200 MB and then drops back to 300 MB after the next test or a few seconds later. Can someone help and give suggestions on how to fix this problem?

I think this is a feature of this drive as it has TLC NAND and only a small SLC cache which is filled quickly, and then performance drops as you experienced. The test on Tom’s Hardware for example showed similar behaviour: https://www.tomshardware.com/reviews/wd-blue-sn570-review/

Best,
Magnus
 
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Device: iMac19,2 2019 – 21.5” - MRT42LL/A (3Ghz i5-8500, Fusion HDD+32GB blade)
Blade upgrade: 32GB Blade -> WD BLUE SN570 500GB
Adapter: Chinese model
Speed test
: 3100 MB/s read, 2200 MB/s write (Blackmagic Disk Speed Test)

Issues after fresh OS install:
The writing speed drops from 2200 MB to 300 MB after a few seconds or the next test. The SSD temperature rises to an average of over 50 degrees Celsius during this time. Again, after a few minutes of retesting, the speed starts at 2200 MB and then drops back to 300 MB after the next test or a few seconds later. Can someone help and give suggestions on how to fix this problem?
Swap it for an SN770 which doesn’t do this.
 
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Swap it for an SN770 which doesn’t do this.
Thanks, but some users have reported experiencing kernel panics and issues after using the sn770 model for a while! It's possible that this could also be an issue with the sn570 model.
 
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