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

[Terraaustralis]

Results: Samsung 980 Pro vs WD Black SN770 on OSX Ventura 2019 iMac.

I have been comparing performance of 2TB Samsung 980Pro versus 2TB WD Black SN770 on 2019 iMac running Ventura 13.5. which is limited to PCIE 3. These days the PCIE 4 NVME drives are cheaper than preceding PCIE 3 models.

Performance: Samsung; Read 3052 Mbps, Write 2960 - WD Black; Read 3038 Mbps, Write,2896 Mbps.
Boot Times of 200GB system heap: Samsung; 16-23 secs. WD Black; 15 secs.
(The variability of Samsung boot up time reflecting the initial incompatibility behaviour which seemed to settle down to 16 secs with use).

Which you prefer will depend upon Platform and o/s.
Both Samsung and WD Black use TLC, but Samsung has AES encryption, uses DRAM and is warranteed for longer life. Samsung offers considerably better sustained write performance. Samsung claim automatic Trim function through Elpis controller for Windows. https://www.tomshardware.com/reviews/samsung-980-pro-m-2-nvme-ssd-review

On Ventura 13.5 Samsung ran smoothly with one exception. At boot-up, the progress bar showed a marked hesitation 40% through completion. This suggested to me an initialisation conflict. Nevertheless once loaded the drive worked smoothly as the above Black Magic numbers indicate.

WD Black SN770 performance matched Samsung but lacks AES security and as a DRAM-less drive uses 64MB of host system RAM for the Controller. It is a very weak performer for sustained writes. In all other respects the drive was smooth and fast which recommends it for OSX.
https://www.tomshardware.com/reviews/wd-black-sn770-ssd-review/2

The absolute decider is Trim
Thank you trs96 for supplying exhaustive and valuable Trim information which I have included in my conclusions.
Given the reluctance of either Apple or Samsung to inform users on the handling of Trim It is reasonable to assume that despite its good performance over a short term test, the Samsung 980 Pro may well accumulate Trim related problems over time. However, according to Spaceman logs, both Samsung and WD Black trims where occurring regularly which appears to absolve doubts about Samsung, at least over the short term.

Apple only support Trim for their own drives. I understand Trim is on for Apple SSD but should be off for non-Apple SSD as many NVME controllers now instigate trim automatically. Which begs the question whether the Samsung Elpis controller is capable of garbage collection for several o/s. So far, Samsung remain silent repeating only the suitability of their drive for Windows 7 upward. This is utterly counterproductive and throws into relief the importance of independent tests and user feedback on sites such as this.

I enabled Ventura o/s trim which slowed the Samsung performance markedly. I also found that as an external boot drive the Samsung was slow with writes 1245 Mbps, Reads 2320Mbps.

For Mac user the WD Black SN 770 is the best choice. Apparently no trim issues. fast operation in external case also; but why, oh why does Western Digital omit AES security in all their drives, at this time when security is so critical?

 

[Terraaustralis]

I think the sensor is needed for the older imacs.

I can say it is not necessary for a 2019 iMac. I would guess it would not be necessary in a 2017 iMac as their design is broadly similar CPU, GPU and RAM distinguish the differences. When SATA upgrade is complete fans race - but once the operating system is configured, Macs Fan Control takes over and software makes sensor unnecessary as temperatures are monitored, reported and fan adjusted within the specs you register in Mac Fan Control preferences.

 

[steve123]

I think the sensor is needed for the older imacs.

You do not actually require a sensor but you do need to make a simple hardware modification on older macs. Here is some useful information:

iMac HDD Thermal Sensor Bypass - LogiWiki

We have Apple MacBook and iPhone Diode readings and general fault finding information compiled by the leaders in this area

logi.wiki

 

[mbosse]

You do not actually require a sensor but you do need to make a simple hardware modification on older macs. Here is some useful information:

iMac HDD Thermal Sensor Bypass - LogiWiki

We have Apple MacBook and iPhone Diode readings and general fault finding information compiled by the leaders in this area

logi.wiki

There is another and pretty much straightforward and simple solution: get the iMac 20" 2008 SuperDrive Thermal sensor cable for a few bucks on Ebay, tape to the SSD and slot cable into the correct socket - everything works fine!

Have done this with a lot of these iMacs back in the days...

Below the cable:

 

[mbosse]

I think the sensor is needed for the older imacs.

Not necessary - with all the various post-2012 iMac (both 21.5" and 27") and different SSDs (Crucial, Micron, Intel, SanDisk, Samsung, WD ...) I never had fans spinning loudly. No special temp sensor cable, no software needed - just install and it works.

I always though had macOS upgraded to the respective latest version, firmware updates inclusive, before I tackled an upgrade.

 

[Tiggmeister]

I just replaced my 128GB Blade and 2TB HDD with this:
GODSHARK M.2 NVME SSD Convert Adapter for MacBook Air Pro Retina Mid 2013 2014 2015 2016 2017, NVME/AHCI SSD Upgraded Kit for A1465 A1466 A1398 A1502. That worked with my
Samsung 990 PRO Series - 2TB PCIe Gen4. X4 NVMe 2.0c - M.2 Internal SSD (MZ-V9P2T0B/AM
My 2015 iMac now boots from that drive. I’m now getting around 2995 MB/s with it compared to my 650 MB/s on the 2TB OWC SSD. Photoshop is good again. The
Sintech NGFF M.2 nVME SSD Adapter Card for Upgrade 2013-2015 Year Macs(Not Fit Early 2013 MacBook Pro) (Black) wouldn’t work with the iMac 17,1. The logic board would even show power. No LED lights showed.

 

[danceswithcamera]

Results: Samsung 980 Pro vs WD Black SN770 on OSX Ventura 2019 iMac.

I have been comparing performance of 2TB Samsung 980Pro versus 2TB WD Black SN770 on 2019 iMac running Ventura 13.5. which is limited to PCIE 3. These days the PCIE 4 NVME drives are cheaper than preceding PCIE 3 models.

Performance: Samsung; Read 3052 Mbps, Write 2960 - WD Black; Read 3038 Mbps, Write,2896 Mbps.
Boot Times of 200GB system heap: Samsung; 16-23 secs. WD Black; 15 secs.
(The variability of Samsung boot up time reflecting the initial incompatibility behaviour which seemed to settle down to 16 secs with use).

Which you prefer will depend upon Platform and o/s.
Both Samsung and WD Black use TLC, but Samsung has AES encryption, uses DRAM and is warranteed for longer life. Samsung offers considerably better sustained write performance. Samsung claim automatic Trim function through Elpis controller for Windows. https://www.tomshardware.com/reviews/samsung-980-pro-m-2-nvme-ssd-review

On Ventura 13.5 Samsung ran smoothly with one exception. At boot-up, the progress bar showed a marked hesitation 40% through completion. This suggested to me an initialisation conflict. Nevertheless once loaded the drive worked smoothly as the above Black Magic numbers indicate.

WD Black SN770 performance matched Samsung but lacks AES security and as a DRAM-less drive uses 64MB of host system RAM for the Controller. It is a very weak performer for sustained writes. In all other respects the drive was smooth and fast which recommends it for OSX.
https://www.tomshardware.com/reviews/wd-black-sn770-ssd-review/2

The absolute decider is Trim
Thank you trs96 for supplying exhaustive and valuable Trim information which I have included in my conclusions.
Given the reluctance of either Apple or Samsung to inform users on the handling of Trim It is reasonable to assume that despite its good performance over a short term test, the Samsung 980 Pro may well accumulate Trim related problems over time. However, according to Spaceman logs, both Samsung and WD Black trims where occurring regularly which appears to absolve doubts about Samsung, at least over the short term.

Apple only support Trim for their own drives. I understand Trim is on for Apple SSD but should be off for non-Apple SSD as many NVME controllers now instigate trim automatically. Which begs the question whether the Samsung Elpis controller is capable of garbage collection for several o/s. So far, Samsung remain silent repeating only the suitability of their drive for Windows 7 upward. This is utterly counterproductive and throws into relief the importance of independent tests and user feedback on sites such as this.

I enabled Ventura o/s trim which slowed the Samsung performance markedly. I also found that as an external boot drive the Samsung was slow with writes 1245 Mbps, Reads 2320Mbps.

For Mac user the WD Black SN 770 is the best choice. Apparently no trim issues. fast operation in external case also; but why, oh why does Western Digital omit AES security in all their drives, at this time when security is so critical?

I'm considering the WD Black SN 850X on my iMac 27" 5K Core i9 2019. Do you know if this would work just as well or possibly better than the WD Black SN 770? Which adapter do you recommend? Sintech? With or without backing?

 

[Lyn2012]

This may not be the best thread to post on but thought I’d give it a try.

I have a late 2014 27” 5K iMac 4GHz i7, 32 GB RAM, 3TB Fusion Drive running High Sierra that I need to update. Having read that APFS doesn’t play well with HDD I’m considering 2 options and would like opinions/advice please.

1. Replace internal HDD with 4TB SSD using this kit. (I’ve upgraded laptops but never opened an iMac before but have watched the video.) Would I need to disconnect/uncouple the Fusion Drive before doing the physical part?

Flexx DIY Bundle with Crucial SSD to swap main HDD for SSD on 27-inch iMac 2012 to 2019

Experience the extreme performance of an Crucial SSD upgrade with this easy DIY SSD and hard drive replacement kit. Add an SSD to your hard drive equipped iMac to experience faster booting, near instant application launches and data transfer speeds up over 500 MB/s.

www.flexxmemory.co.uk

2. Buy a thunderbolt SSD, probably 2TB because of cost, and use this instead of internal drive. Would I be able to then use the 3TB internal drive as extra storage, any problems reading/writing between APFS and older file system? Sorry if these are basic questions. Recommendations for drive please as I understand Trim may cause problems.

All advice, opinions and recommendations regarding these options would be appreciated. Please note I am in the UK so please use parts available over here. Also would Catalina or Big Sur be the best O/S to use?

TIA

 

[Terraaustralis]

I'm considering the WD Black SN 850X on my iMac 27" 5K Core i9 2019. Do you know if this would work just as well or possibly better than the WD Black SN 770? Which adapter do you recommend? Sintech? With or without backing?

While I have no personal experience using the WD850X in a 2019 iMac I have read on MacRumors that others have used it without problems and I believe it is one of the SSD’s recommended by MacRumors. Please confirm this to your own satisfaction with a search. Personally I feel confident you are on safe ground. However I cannot recommend without personal experience. At PCIE 3 speeds you probably will get at least 3200Mbps.

I used a Sintech adapter as the SN770 is single sided. The SN850X comes contained in unit with a heatsink. I suspect the short adapter is a better fitting for the SN850X as the NVME runs hot and the Sintech base will limit airflow around the SSD and inhibit cooling. Maybe at PCIE speeds temperature will not be an issue. You should be OK with the short adapter. They fit tight and firm. You can buy both from Ali Express much cheaper than Amazon. The short Macbook adapter by NFHK is sold by both Ali Express and Amazon.

The 2019 Motherboard PCIE fitting has a cowel which prevents shorting and if the PCIE adapter is firmly seated and the NVME firmly seated, you should have no problems. These fittings require firm pressure. Before you close the screen up. plug in power then switch on iMac and read the 1 to 5 pilot lights on the Motherboard, (top right section). 4 will be off as the screen is not connected, but the other lights should show green and confirm the power circuitry, gpu/cpu connections are all OK. That means your SSD is working properly. Please wear surgical gloves for the entire upgrade process and be very careful handling power board. I work with the imac on its back. Switch off computer before pulling power plug out. That sounds obvious but repair technicians comment that people concentrate on the unfamiliar assembly process and forget resulting a dead screen.

If you buy the SSD from a reputable dealer offering a good refund service such as Amazon. open tho drive package carefully, You may be able to un-stick and re-stick the package seal, so it can be returned with minimum damage. Don’t slit the instruction sheets (which offer nothing but warranty translations). Claim incompatibility and you should be safe for a full refund. It worked for me with an Amazon refund for a Samsung SSD.

Tell me what speeds you achieve.

Hope that helps.
Cheers

 

[Yiveymacnod]

While I have no personal experience using the WD850X in a 2019 iMac I have read on MacRumors that others have used it without problems and I believe it is one of the SSD’s recommended by MacRumors. Please confirm this to your own satisfaction with a search. Personally I feel confident you are on safe ground. However I cannot recommend without personal experience. At PCIE 3 speeds you probably will get at least 3200Mbps.

I used a Sintech adapter as the SN770 is single sided. The SN850X comes contained in unit with a heatsink. I suspect the short adapter is a better fitting for the SN850X as the Sintech runs hot and the Sintech base will limit airflow around the SSD and inhibit cooling. You should be OK with the short adapter. They fit tight and firm. You can buy both from Ali Express much cheaper than Amazon. The short Macbook adapter by NFHK is sold by Ali Express and Amazon.

The 2019 Motherboard PCIE fitting has a cowel which prevents shorting and if the PCIE adapter is firmly seated and the NVME firmly seated, you should have no problems. These fittings require firm pressure. Before you close the screen up. plug in power then switch on iMac and read the 1 to 5 pilot lights on the Motherboard, (top right section). 4 will be off as the screen is not connected, but the other lights should show green and confirm the power circuitry, gpu/cpu connections are all OK. That means your SSD is working properly. Please wear surgical gloves for the entire upgrade process and be very careful handling power board. I work with the imac on its back. Switch off computer before pulling power plug out. That sounds obvious but repair technicians comment that people concentrate on the unfamiliar assembly process and forget resulting a dead screen.

If you buy the SSD from a reputable dealer offering a good refund service such as Amazon. open tho drive package carefully, You may be able to un-stick and re-stick the package seal, so it can be returned with minimum damage. Don’t slit the instruction sheets (which offer nothing but warranty translations). Claim incompatibility and you should be safe for a full refund. It worked for me with an Amazon refund for a Samsung SSD.

Tell me what speeds you achieve.

Hope that helps.
Cheers

Just FYI, the SN850x comes in two versions. Both with and without a heatsink. Other than that your information is 👍

 

[Terraaustralis]

Just FYI, the SN850x comes in two versions. Both with and without a heatsink. Other than that your information is 👍

Thank you. A point which deserves mention. I was more concerned about double or single sided blade for fitting the appropriate adapter. I reckon Dances with Camera will adjust information to suit his purchase.
Cheers,

 

[danceswithcamera]

Thank you. A point which deserves mention. I was more concerned about double or single sided blade for fitting the appropriate adapter. I reckon Dances with Camera will adjust information to suit his purchase.
Cheers,

Thank you for your advice. I have decided to get the short adapter without the base, so I won't have worry about whether the SSD is single- or double-sided. Is there any reason for choosing the long version vs the short version?

Thank you also for the advice about using surgical gloves and about how to handle the power board. I certainly don't want to get shocked or blow out the iMac while working on it.

I had another question about the diagnostic LEDs on the motherboard. I understand that LED #1 lighting up green indicates that the power is plugged in, and #1 & #2 lighting up indicates that the power is plugged in and the power is on. What do LEDs #3-5 indicate?

I appreciate all the advice from everyone in the forum. Although I had just joined a couple if days ago, It has been really helpful and it gave me more confidence about the upgrading process and the SSD and adapter purchases.

Cheers everyone.

 

[danceswithcamera]

I accidentally posted the same message twice. So, I deleted it and wrote this message, as I wasn't able to find a way to delete the post.

 

[Terraaustralis]

This may not be the best thread to post on but thought I’d give it a try.

I have a late 2014 27” 5K iMac 4GHz i7, 32 GB RAM, 3TB Fusion Drive running High Sierra that I need to update. Having read that APFS doesn’t play well with HDD I’m considering 2 options and would like opinions/advice please.

1. Replace internal HDD with 4TB SSD using this kit. (I’ve upgraded laptops but never opened an iMac before but have watched the video.) Would I need to disconnect/uncouple the Fusion Drive before doing the physical part?

Flexx DIY Bundle with Crucial SSD to swap main HDD for SSD on 27-inch iMac 2012 to 2019

Experience the extreme performance of an Crucial SSD upgrade with this easy DIY SSD and hard drive replacement kit. Add an SSD to your hard drive equipped iMac to experience faster booting, near instant application launches and data transfer speeds up over 500 MB/s.

www.flexxmemory.co.uk

2. Buy a thunderbolt SSD, probably 2TB because of cost, and use this instead of internal drive. Would I be able to then use the 3TB internal drive as extra storage, any problems reading/writing between APFS and older file system? Sorry if these are basic questions. Recommendations for drive please as I understand Trim may cause problems.

All advice, opinions and recommendations regarding these options would be appreciated. Please note I am in the UK so please use parts available over here. Also would Catalina or Big Sur be the best O/S to use?

TIA

I have opened 2011 and 2019 iMac. Each model has internal differences but the process of access and configuration are similar. In response to your questions I make technical comment and you need to evaluate preference according to your budget.
1. For general usage APFS plays fine with HDD. Articles such as the following apply to a given point of time in history https://www.lifewire.com/apfs-on-different-disk-types-4155143
Notwithstanding the validity of the fragmentation argument, I suspect Apple have provided for the problems described in the article. APFS is mandatory for High Sierra upwards and Fusion drives continue to function reliably. Despite the millions of Fusion drives out there, I have read no complaints about copying or fragmentation glitches.

2. Internal vs external SSD. Internal is faster, cheaper and neat as cables and external container unnecessary. Assuming you have the technical skills to handle opening and closing iMac. See item 4. A SATA SSD gives a snappy boost to iMac and is easy to install. An NVME internal SSD is more work and you are generally limited to WD Black NVME for speed and compatibility. Other brands, Crucial and Sabrent Rocket also work but check Page One of this Blog to see what suits your 2014 iMac.
If you do Video, very large file transfers or are a gamer, the NVME is worth considering. In my 2019 iMac I get 2900 Mbps in both write and Read with the WD Black SN770. The Samsung 870 Evo SATA SDD I installed gives around 470 Write to 500 Read Mbps, close to SATA bandwidth limit. Actual speeds always fall below advertised benchmarks.

3. External SSD’s are many and expensive. The best argument for external equipment is the ability to transfer to other devices and general portability particularly for Macbooks.
Using an external bootable 2TB SSD is feasible but I would not recommend it for standard practice. Boot time and drive performance are inevitably slower than the internal option. Also you isolate the external Apple o/s from security upgrades and hardware testing. Not a good idea.
I use a 1 TB Samsung T7 external bootable drive as an emergency o/s only with a clone of my entire system. All daily operations are on the iMac and TM backup is also available on another external T7.

4. Your most cost effective option is to buy a 4TB SATA SSD but the Crucial kit only offers 2TB max. Read this carefully and you may find buying individual items more cost efficient.

iMac (Retina 5K, 27-inch, 2017) CPU and NVME SSD Upgrade Pitfalls and Tips

iMac (Retina 5K, 27-inch, 2017) CPU and NVMe SSD Upgrade Pitfalls and Tips UPDATE: Information regarding upgrading the 2019 27-inch IMac with the Intel i9-9900K CPU and 2TB Samsung 970 EVO NVMe SSD can be found in the post below...

forums.macrumors.com

That said, Ali Express will save you money and the tools are just as good as those in US and UK See this kit at US$69.00. This kit below, I use at US$13-00

31.23US $ |60/62 in 1 Precision Torx Screwdriver Sleeve Set Portable Cloth Cover Home PC Mobile Phone Disassembly Tool Combination Repair| | - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

For adhesive strips and tool https://www.aliexpress.com/item/100...ea!AU!3569443149!S&curPageLogUid=RUV32tnwz3bd

With Christmas approaching you will find deals for purchasing a 4TB SATA SSD.

Hope this helps.
Cheers,

 

[Terraaustralis]

Thank you for your advice. I have decided to get the short adapter without the base, so I won't have worry about whether the SSD is single- or double-sided. Is there any reason for choosing the long version vs the short version?

Thank you also for the advice about using surgical gloves and about how to handle the power board. I certainly don't want to get shocked or blow out the iMac while working on it.

I had another question about the diagnostic LEDs on the motherboard. I understand that LED #1 lighting up green indicates that the power is plugged in, and #1 & #2 lighting up indicates that the power is plugged in and the power is on. What do LEDs #3-5 indicate?

I appreciate all the advice from everyone in the forum. Although I had just joined a couple if days ago, It has been really helpful and it gave me more confidence about the upgrading process and the SSD and adapter purchases.

Cheers everyone.

 

[Terraaustralis]

Regarding long vs short PCIE/NVME adapter, my impression is Sintech was found to be a reliable product by Dobrink and rsx0 back in 2017-18. Products from China tended to receive disparaging remarks by some bloggers. Now, in 2013, I the situation is different. One must be careful buying from China - check the feed back - but Amazon and Fixit are selling Chinese products at x2 x4 times the original price. The short adapter is a case in point. I have purchased one from Amazon and two from China. All three worked equally well. NFHK labelled items seem well made. Back in the day Chinese products were not trusted and criticised as substandard. So far purchases of RAM, tools etc. have worked for me.

Another example is seals and wheel tool for screen removal. Ifixit charged AUD$34-00 for one set of adhesive with wheel tool. I purchased 5 sets for AUD$19.00 from China. Apart from Ifixit having numbered each strip, the products appear exactly the same. The Ifixit wheel tool is supplied in a box showing it is made in China. Again, Stories of people damaging screens and blaming adhesive are impossible to rely upon. Did they clean off all the old adhesive with Isopropyl alcohol? Did they burnish the adhesive strips onto the iMac properly? Did they leave the iMac face down on a towel for 24hrs? exactly how careful are these people? Poor technique is probably the cause of many of these failures. Easier to blame the adhesive. I read OWC produce adhesive strips without a foam core. These were criticised as too thin for future removal. If so, a valid observation.

I favour Surgical gloves with added soy because they slip on and off more easily. I favour gloves as the wrist strap coiled cable catches on items and gets in the way. I have damaged a power unit without being aware of how it happened. The slightest brush on a condenser terminal can do it. I have carpeted floor and clean formica desktop. I am sure static build-up in my body is significant and there is no steel fitting available to ground the charge. The iMac is Aluminium which is a weak conductor. Surgical gloves offer both good grip and good insulation. Personally I prefer to work with the iMac on its back after cutting the adhesive with a scalpal. I prop the screen up a few inches, very carefully remove cables before lifting and removing screen. In particular the LCD cable between motherboard and screen deserves great care as the 60 pin connector is easily damaged. Essential not to open the screen too far and strain a cable connection.

Diagnostic LED’s:
1 = AC input voltage (trickle power present)
2 = Power supply DC output voltage
3 = Memory is functioning
4 = GPU is functioning
5 = Display panel is connected

See rsx0 below for more information about LED’s.

I am sure all of us are greatly appreciative and indebted to Dobrink for establishing this thread: https://forums.macrumors.com/threads/a-list-of-successful-imac-27-2012-2019-ssd-upgrades.2162435/

And to rsx0 for expanding extensive detail with this thread: https://forums.macrumors.com/thread...d-nvme-ssd-upgrade-pitfalls-and-tips.2177812/

They and all other contributors have empowered we DIY amateurs and saved us both money and anxiety by providing facts and experience. I salute you!

Take your time and fully read the above information. Even information not directly relevant to your purpose can later be useful. Allow it is 5 years old and do your research on current products.

Best Wishes.

 

[Lyn2012]

I have opened 2011 and 2019 iMac. Each model has internal differences but the process of access and configuration are similar. In response to your questions I make technical comment and you need to evaluate preference according to your budget.
1. For general usage APFS plays fine with HDD. Articles such as the following apply to a given point of time in history https://www.lifewire.com/apfs-on-different-disk-types-4155143
Notwithstanding the validity of the fragmentation argument, I suspect Apple have provided for the problems described in the article. APFS is mandatory for High Sierra upwards and Fusion drives continue to function reliably. Despite the millions of Fusion drives out there, I have read no complaints about copying or fragmentation glitches.

2. Internal vs external SSD. Internal is faster, cheaper and neat as cables and external container unnecessary. Assuming you have the technical skills to handle opening and closing iMac. See item 4. A SATA SSD gives a snappy boost to iMac and is easy to install. An NVME internal SSD is more work and you are generally limited to WD Black NVME for speed and compatibility. Other brands, Crucial and Sabrent Rocket also work but check Page One of this Blog to see what suits your 2014 iMac.
If you do Video, very large file transfers or are a gamer, the NVME is worth considering. In my 2019 iMac I get 2900 Mbps in both write and Read with the WD Black SN770. The Samsung 870 Evo SATA SDD I installed gives around 470 Write to 500 Read Mbps, close to SATA bandwidth limit. Actual speeds always fall below advertised benchmarks.

3. External SSD’s are many and expensive. The best argument for external equipment is the ability to transfer to other devices and general portability particularly for Macbooks.
Using an external bootable 2TB SSD is feasible but I would not recommend it for standard practice. Boot time and drive performance are inevitably slower than the internal option. Also you isolate the external Apple o/s from security upgrades and hardware testing. Not a good idea.
I use a 1 TB Samsung T7 external bootable drive as an emergency o/s only with a clone of my entire system. All daily operations are on the iMac and TM backup is also available on another external T7.

4. Your most cost effective option is to buy a 4TB SATA SSD but the Crucial kit only offers 2TB max. Read this carefully and you may find buying individual items more cost efficient.

iMac (Retina 5K, 27-inch, 2017) CPU and NVME SSD Upgrade Pitfalls and Tips

iMac (Retina 5K, 27-inch, 2017) CPU and NVMe SSD Upgrade Pitfalls and Tips UPDATE: Information regarding upgrading the 2019 27-inch IMac with the Intel i9-9900K CPU and 2TB Samsung 970 EVO NVMe SSD can be found in the post below...

forums.macrumors.com

That said, Ali Express will save you money and the tools are just as good as those in US and UK See this kit at US$69.00. This kit below, I use at US$13-00

31.23US $ |60/62 in 1 Precision Torx Screwdriver Sleeve Set Portable Cloth Cover Home PC Mobile Phone Disassembly Tool Combination Repair| | - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

For adhesive strips and tool https://www.aliexpress.com/item/1005003063524711.html?spm=a2g0o.productlist.main.1.49f4687bM2hY69&algo_pvid=ce46fd1b-e18a-464c-9de3-caee4836a875&algo_exp_id=ce46fd1b-e18a-464c-9de3-caee4836a875-0&pdp_npi=4@dis!AUD!28.77!27.33!!!18.17!!@2101f49d16953572723052554e1aef!12000032664135439!sea!AU!3569443149!S&curPageLogUid=RUV32tnwz3bd

With Christmas approaching you will find deals for purchasing a 4TB SATA SSD.

Hope this helps.
Cheers,

Thank you so much for such a detailed reply with all the info. I think I will go ahead and attempt replacing the internal HDD myself. The Flex kit I’m looking at includes this SSD, would this be OK? Crucial MX500 SSD 4TB

 

[Terraaustralis]

Thank you so much for such a detailed reply with all the info. I think I will go ahead and attempt replacing the internal HDD myself. The Flex kit I’m looking at includes this SSD, would this be OK? Crucial MX500 SSD 4TB

I have no experience of Crucial SSD. Use the Dobrink link I supplied to read about which other SSD’s have been used for a 2014 iMac. Don’t get stuck on that particular package deal. Crucial has been used by MacRumors mebers but on which iMacs I cannot remember.

 

[tvv]

I read OWC produce adhesive strips without a foam core. These were criticised as too thin for future removal. If so, a valid observation.

The OWC strips have a foam core.

 

[Terraaustralis]

Live and Learn!
Thank You.

 

[danceswithcamera]

Just FYI, the SN850x comes in two versions. Both with and without a heatsink. Other than that your information is 👍

Do you recommend having a heatsink? I have read that a heatsink is really not needed, especially if you're not doing any heavy read/write. What is your view on this? Also, which 2.5" internal SSD would you recommend as the second drive for the fusion drive? Or, do you prefer to stay away from the fusion drive setup?

 

[macguru9999]

My advice is to install a crucial 1,2 or 4tb sata ssd in place of the HDD. If you have an apple ssd on the mobo leave it alone, or format it apfs and delete the volume to keep it hidden, its too small to mess with usually. BUT, it you must tinker and its a 2017 or 2019 imac then you can fit an nvme ssd with adapter in but i dont think its worth the trouble, but say you have the 21.5in imac mobo out to add ram and there happens to be an ssd slot , then sure....... you could add an 8 or 4tb ssd. The trouble with the older imacs is that the firmware was not updated for nvme and they can crash. Of course, you could add an apple non nvme ssd if you have one, to an older imac 2013-2015

 

[Terraaustralis]

Do you recommend having a heatsink? I have read that a heatsink is really not needed, especially if you're not doing any heavy read/write. What is your view on this? Also, which 2.5" internal SSD would you recommend as the second drive for the fusion drive? Or, do you prefer to stay away from the fusion drive setup?

I have a heatsink on the 2TB WD SN770 NVMe. It does no harm and temperature cooling is covered. While the S770 is a PCIE 4.0 NVMe, my iMac is PCIE 3.0 and probably the heatsink is superfluous as it works at half speed by comparison with its intended use.

As a video creator, being one of the best drives for sustained copying, I prefer Samsung when possible. I tried a Samsung 980 Pro which ran at 3100MB/s for both read and write but the iMac was unhappy with it. I finally decided the SN770 was a more Apple compatible NVMe.

Samsung works fine for the 2TB SATA SSD. I use an 870 Evo which performs at 2800 MB/s write and 2900 MB/s read. start-up time is: Samsung 870 Evo SSD, 16 secs: WD SN770, 20 secs. both tested with a 400GB system heap. Of course the SATA SSD runs at 500MB/s which is much faster than Fusion.

I am not running Fusion as it seems no longer necessary. That means I have internal 2 x 2TB SSD drives. I operate daily on the SN770 and store completed video and image files on the Evo 870. The 870 Evo SSD needs no internal cable temperature sensor as Macs Fan control software handles temperature control perfectly.

I tested the 128 Apple SSD in isolation and found it ran Read 370MB/s Write 700MB/s. Clearly it is designed for fast reads but is hardly of value once you have a SATA SSDdrive. Remember ,Fusion was designed to make an HDD iMac operate faster. Now, SSD’s are so much cheaper than in 2012, Fusion offers no advantage.

If you have no need to replace it, you can ignore the small 128Gb Apple SSD, boot up and work off your 4TB SATA SSD and I think you will be very happy.

I trust that helps.

 

[danceswithcamera]

I have a heatsink on the 2TB WD SN770 NVMe. It does no harm and temperature cooling is covered. While the S770 is a PCIE 4.0 NVMe, my iMac is PCIE 3.0 and probably the heatsink is superfluous as it works at half speed by comparison with its intended use.

As a video creator, being one of the best drives for sustained copying, I prefer Samsung when possible. I tried a Samsung 980 Pro which ran at 3100MB/s for both read and write but the iMac was unhappy with it. I finally decided the SN770 was an Apple compatible NVMe.

Samsung works fine for the 2TB SATA SSD. I use an 870 Evo which performs at 2800 MB/s write and 2900 MB/s read. start-up time is: Samsung 870 Evo SSD, 20 secs: WD SN770, 30 secs. both tested with a 400GB system heap. Of course the SATA SSD runs at 500MB/s which is much faster than Fusion.

I am not running Fusion as it seems no longer necessary. That means I have internal 2 x 2TB SSD drives. I operate daily on the SN770 and store completed video and image files on the Evo 870. The 870 Evo SSD needs no internal cable temperature sensor as Macs Fan control software handles temperature control perfectly.

I tested the 128 Apple SSD in isolation and found it ran Read 370MB/s Write 700MB/s. Clearly it is designed for fast reads but is hardly of value once you have a SATA SSDdrive. Remember ,Fusion was designed to make an HDD iMac operate faster. Now, SSD’s are so much cheaper than in 2012, Fusion offers no advantage.

If you have no need to replace it, you can ignore the small 128Gb Apple SSD, boot up and work off your 4TB SATA SSD and I think you will be very happy.

I trust that helps.

Very helpful information. Thank you very much. I'm considering going with the WD Black SN850x 2tb with heatsink as my OS drive and the Samsung 870 EVO 1tb as an extra internal SATA SSD drive. I plan to keep them as separate drives, no fusion. I will post my results once I get the upgrade done. Thank you again for all the information and advice.

 

[Terraaustralis]

Very helpful information. Thank you very much. I'm considering going with the WD Black SN850x 2tb with heatsink as my OS drive and the Samsung 870 EVO 1tb as an extra internal SATA SSD drive. I plan to keep them as separate drives, no fusion. I will post my results once I get the upgrade done. Thank you again for all the information and advice.

As a PCIe 4.0, the WD SN850 will be running at about half speed. I would be interested to see your Black Magic disk results and your 27" iMac system heap, start time from chime, CPU and memory specs.
I purchased a PCIE 4.0 WD SN770 because it was cheaper than the PCIE 3.0 drives I looked at. Perhaps like you, I figured I may at some future time use the NVME as an external drive for an iMac.
Good Luck with the upgrade.