I used to use SM951 AHCI in Mac Pro 5.1, 6.1, all Retina and Air 2013-2015 but what about NVMe once? Have anyone tried?

⟐ Commented November 28, 2025 at 13:00 MST

I installed 64GB of RAM into my iMac 4 x 16GB

After the upgrade the system fails to boot. I can hear the hard drive, however the screen is off, with the old RAM the iMac works as expected.

I have verified that the RAM is compatible and should work with my iMac.

Any solution to get the iMac to work with the new RAM?

⟐ Commented April 19, 2024 at 12:48 MST

So... The New Intel CPU 8700K is now available!

I just want know can I replace my i5 7600k to the new i7 8700k?

Is it possible to upgrade?

Thank You So Much

⟐ Answered May 30, 2023 at 9:28 MST

But the main point I need the OS & software run it faster instead of need a largest storage. Just wondering is easy to change it to SSD if the specs is Fusion Drive not. Or get the SSD specs is better, so if need to upgrade in future is still feasible.

⟐ Answer edited April 20, 2024 at 14:32 MST

These questions are very important to me:

• The HDD is upgradable without needing a thermal sensor?
• Is the CPU upgradable?
• Number phases CPU? GPU?
• Model number memory GPU ?

Can I update my CPU i5 3.8 (7600k) with i7 4,2 (7700k), the phase corresponding in watt?

Thank you in advance.

⟐ Commented April 23, 2021 at 7:49 MST

⟐ Answer edited September 17, 2025 at 8:59 MST

First part: 970 EVO NVMe with heatsink installed. Recognized @ Link x4 and great speed. SSD installed and MacOS Catalina reinstalled. Very happy so far.

Second part, a day after: Removed CPU, installed i7-7700k. Struggled a bit with heatsink like everyone it seems. But once done I felt confident that everything was done right, so I re-assembled everything. But the power switch didn't trigger anything!

• LED 1 is on as soon as I connect the iMac to the external power cord.
• Power switch cable seems intact and connected to PSU. PSU and logic board cables all disconnected/reconnected with great care and seem intact.
• Tried to short both power switch pin to start up the Mac. Nothing happened.

Does anyone have any suggestions or comments on what the problem may be?

• I've ordered a new PSU for safe measure. I can't find a spare power switch button (the only part available that has it is an entire empty housing!).
• Can't find a spare power supply control cable (between PSU and Logic board) for a 2017 iMac. But there are some for the 2011-2013 iMac which looks the same as for the 2017 version.
  

Tempted to order that. Does anyone know if the 2013 and 2017 use the same power control cable?

After discussing with friends, one plausible explanation could be that my CPU upgrade went bad. Such as static electricity frying the Logic board. Or the CPU is bad. Even though I've been careful all the way. However, if I understand the explanations regarding the logic board LEDs function, it seems that not even having the LED 2 or 3 on would mean my issue isn't yet entirely related to the Logic board or the CPU. Anyone can comment on this?

I would be very grateful for any suggestions (at least it'll boost my morale, as right now if the new PSU doesn't work, I would have probably to sell the iMac for parts!!)

Thanks

Seb

Just received the new PSU (see picture). Installed carefully (making sure I discharge any static electricity from my hands prior). Reconnected all wires, after inspecting them (see picture). And unfortunately I have the same result: the power switch, which seems to be 100% intact (see pictures), doesn’t trigger any response. Fan doesn’t spin. No second LED.

Could it be the main power cable socket (buried under the bottom bezel of the imac housing)??

Any suggestions welcomed!

Disassembled the Mac again. Look very carefully for damaged cables, or sockets… None found! Took a picture of the wires coming from the main power socket (see below). Everything looks fully functional.

Could this be a back Logic Board??

I can finally breath: Removed the new CPU, installed the old CPU and I’ve got the board to boot up. Did not perform a full reboot with the LCD on. I will make another attempt at upgrading tomorrow with another CPU, so I had only the PSU and Logic board mounted.

Is this a Bad CPU or it wasn’t mounted right, I can’t say for sure. But the Fan started to spin at max speed without stopping, so that got me thinking and decided to go for the i7-7700 instead of the 7700k!

Now, I got to improve my tension spring loading technique. I concur with others that the tension produced by this spring is excessive (Judging from the residue of thermal paste which had been completely squeezed out to the sides when I removed the CPU). So I’ve kept a more important gap between the mounting spring and the logic board, than what I had originally measured (<1mm). See pictures.

Hopefully my next post will be about completing this job… Wish me luck.

Final update: Finally got the system to work.

How: The short answer is you have to unbend the metal spring underneath the CPU!

There is way too much tension in this spring, this put so much strain on the CPU that it bends it. Some pins are then no longer connected. When the LED 1 or 1-2 lit up and nothing more it just means that.

I’ve tried a i7-7700k twice, reinstalled the i5-7600, then tried and kept a i7-7700 finally. So I’ve got plenty of trials to figure all this out.

I will now answer questions :)

⟐ Commented July 15, 2025 at 10:24 MST

⟐ Commented May 15, 2020 at 16:28 MST

⟐ Answer edited September 28, 2023 at 18:01 MST

If it doesn't work, which one should I get?

Thanks

Hi Dan

Yes, I'm sure (I'm attaching the image). I think it's a 2 lane SSD because it is Fusion Drive.

In the image you can see the characteristics of the ssd of the imac 2017

Thanks

⟐ Commented March 01, 2023 at 2:12 MST

I understand that such iMac has two different ports for two different disks inside (eg., one SSD or one Fusion drive from Apple).

Questions:

1. Is it possible to install this disk inside to boot the iMac?

Samsung 960 PRO Series - 2TB PCIe NVMe - M.2 Internal SSD (MZ-V6P2T0BW)

Sequential R/W (read/write) speeds up to 3,500/2,100 MB/s and random R/W speeds up to 440/360K IOPS, respectively.

• Samsung 960 PRO M.2 NVMe SSD
• Amazon - Samsung 960 PRO M.2 NVMe SSD 2TB

2. Is it possible to have two SSD at the same time inside the iMac?

For instance, the one SSD from Apple (or the one above, if possible) and other like this (now 2TB, soon 4TB)?

Samsung 850 PRO - 2TB - 2.5-Inch SATA III Internal SSD (MZ-7KE2T0BW)

Sequential Read/Write Performance: Up to 550MB/s and 520MB/s, respectively. Random Read/Write IOPS Performance: Up to 100K and 90K, respectively.

• Samsung 850 PRO 2.5" SATA SSD
• Amazon - Samsung 850 PRO 2.5" SATA SSD - 2TB

Thanks!

⟐ Comment deleted March 26, 2022 at 12:41 MST

⟐ Commented October 13, 2018 at 0:43 MST

So if there's no one can answer this question right now, I'll just leave this question here and if someone have the same concern later, maybe there will be a answer then.

(Maybe I'll answer this question myself then)

This is case shows all 300 imac (2015 version) have dust in their screens.

⟐ Answered October 28, 2022 at 13:53 MST

Can it be replaced with older (2014/2015) models displays?

⟐ Answer accepted November 17, 2025 at 20:08 MST

⟐ Commented February 21, 2025 at 19:00 MST

⟐ Answer edited November 21, 2021 at 13:47 MST

I have almost the same question !

iMac 5k i7 / 18.3 late 2017

What kind of SSD blade fit with my iMac ?

APPLE SSD SM0128L

• Révision : CXS7CA0Q
• Numéro de série : S3CWNY0J946659
• Largeur du câble : x4
• Vitesse de la liaison : 8.0 GT/s

⟐ Commented January 07, 2021 at 23:32 MST

Last year I bought a base model iMac 5K and it was working fine for me but my work has intensify and I would like to upgrade the CPU to an i7 and the HDD to and SSD .

My question is: Now that Apple lunched the Eight Gen CPU's in the new Macbook Pro. Can I opt for the 8700K(or any variant of it) instead of the 7700K?

⟐ Answer accepted April 26, 2019 at 5:22 MST

My 2017 iMac is getting a bit long in the tooth but I don't have the money to replace it.

Would it be possible to replace the old logic board with a newer version from a donor 2019 or 2020 model? I've read contrary information online. Most people say it's not possible. One guy said he tried it with a 2019 board and it worked fine.

Does anyone have experience trying this before I pull the trigger?

Thanks

⟐ Answer edited March 24, 2024 at 1:12 MST

Thank you.

⟐ Commented October 23, 2019 at 12:56 MST