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

[Ruadh]

I would suggest NOT to remove heatsink (to redo thermal paste). It is a bad design and it is clumsy to reinstall heatsink, risking damage to CPU.

I agree that it is a bad design. The instructional videos that I've reviewed show some failed installs, where the heat sink fell off the mother board before it could be fixed down, thus ruining the thermal paste and maybe damaging the CPU pins.

However, the instructional video that I'm going to follow took care to have all screws and fixings ready, firmly clasped the heat sink to the mother board after redoing the thermal paste, then inverted the pair and screwed them together in one careful move. That included screwing down the Torx screws in the same way that I would install a head to an engine, one turn at a time, rotating diagonally between screws. That obviously will take dexterity and patience, so I appreciate the risk, but I am prepared to bet that I have the experience to do it.

 

[Ruadh]

You will probably find it is the BR2032. You can replace it with CR2032 if you can't source BR2032.

Regarding battery, yes. Cheap to buy, easy to do.

I could not find the battery at Battery World or other battery suppliers. At online IT part wholesalers it was AUD20 (USD13) plus delivery. However, I found a local wholesaler who did it for AUD6 (USD3.75) and my son will pick it up on his way home, so no delivery cost or delay.

I don't see any point buying the CR2032. It would make more sense to leave the current BR2032 in if I hadn't been able to source one.

 

[Ruadh]

It seems the only sure way is to open the iMac, look inside and then order what you need.

Yes, I'll tell you what I find when I open it up, hopefully over the weekend.

Internal HDD or not, you will need the Sabrent adapter or similar to fit the 1TB 2.5" OWC SATA to existing HDD lugs moulded into iMac case.

I have a Newertech AdaptaDrive that I got from OWC with a previous upgrade, that I will see if it can be adapta'd.

 

[Ruadh]

If you intend using a WD Black NVMe, which is recommended as compatible with Apple, do not buy a Sintech converter, it is not compatible with WD Black.

Sorry - afterthought on something I already replied to. As you know, I bought the WD Blue nvme, the difference with WD Black being, I understand, that Blue does not have NAND, which is cheaper, potentially faster for sequential read/write, but slower for random write.

When you said WD Black, was the incompatibility related to NAND, and so the WD Blue would be okay with Sintech, or am I taking you too literally?

 

[Terraaustralis]

Yes, I'll tell you what I find when I open it up, hopefully over the weekend.



I have a Newtech Adaptadrive that I got from OWC with a previous upgrade, that I will see if it can be adapta'd.

Newtech is ideal !
Cheers,

 

[mwidjaya]

I have a Newtech Adaptadrive that I got from OWC with a previous upgrade, that I will see if it can be adapta'd.

I don't see the need for adapter, since it is a stationary desktop.

With SSD (no moving parts), you just need to secure it anyway you can. I have seen people use double sided tape/velcros to stick it to imac's metal shell.

Here is an example.

 

[Terraaustralis]

Sorry - afterthought on something I already replied to. As you know, I bought the WD Blue, the difference with WD Black being, I understand, that Blue does not have NAND, which is cheaper, potentially faster for sequential read/write, but slower for random write.

When you said WD Black, was the incompatibility related to NAND, and so the WD Blue would be okay with Sintech, or am I taking you too literally?

From my experience with the WD Black SN770, which does not have NAND and uses the Host Memory Buffer (HMB) design - same as SN580 - a slower NVMe; both use computer RAM to replace NAND storage.

HMB is fast, efficient and runs cooler with lower sustained write performance than premium NVMe SN850x with its own NAND. Main shortcoming with non NAND NVMe is with sustained writes as you mention, which drop speeds to a mere 500MBs after a solid sustained 100 secs transfer when cache becomes full. A break in data transfer enables fast cache refreshment, so data transfer then resumes at high speed. The HMB design is good for mixed file transfer such as general office/ publishing DTP work.
Gamers and large photo/video file transfer users appreciate the SN850x and can justify paying $100 or more above SN770.

Cannot find the original reference, but memory tells me WD Blue SN570, Black SN770 are listed as Sintech incompatible by both Sintech and WD Black. May also apply to SN580 which is a new modification. Email WD and or Sintech support to confirm status of SN580.

 

[mbosse]

A few comments here to clear some misconceptions:

Fusion is a hybrid of two drives whose icons are visible on your desktop. One which you name, and the other by default is named ‘Mackintosh HD’. That would be the HDD. If only one drive icon is on the desktop, that would be your solo 2TB SSD. Can you remember the number of desktop drive icons?

This is actually not the case. Correct is that a FusionDrive is a hybrid of two drives (like a RAID-0 of some specialised sort) but there is only one single desktop icon named 'Macintosh HD', not two as you suggest. One drive is a SSD, the other is a conventional spinning hard drive. macOS dynamically distributes your data between the two to give you a responsive experience based your use pattern without the costs of a similar sized SSD.

Both a Fusion Drive as well as single internal SSD (or hard drive for that matter) would show exactly the same one icon on the desktop.

From my experience with the WD Black SN770, which does not have NAND and uses the Host Memory Buffer (HMB) design - same as SN580 - a slower NVMe; both use computer RAM to replace NAND storage.

I think you're mixing up NAND and DRAM. An SSD without NAND would simply have no capacity to store any data... DRAM (Dynamic Random-Access Memory) which is a fast volatile memory which is used a buffer mostly for cheaper SSDs to temporarily store data which is to be written to the usually slower NAND of budget SSDs. The WD Black SN770 uses Kioxia BiCS5 112L TLC NAND btw.

Install a 1TB OWC 6G 2.5" SSD that I've pulled out of my dead MacBook. I've ordered the appropriate SATA cable. I know I could do this externally, but I already have an External drive and my hub slots are full.

Be aware that if you ordered an iMac with a single SSD only you won't have the iMac SATA cable and also might likely miss the mounting material. But glueing it in place would certainly be sufficient as no mechanical parts inside. As regards to an SSD, OWC has a bit of a shaky reliability record as well has repeatedly been caught with promises regarding Apple compatibility which proved incorrect, I'd personally use a Samsung like a 870 Evo or Pro (don't opt for a QVO as this has little endurance!). Most Apple SSDs are based on Samsung models anyway so there little compatibility issues as long as SATA SSDs are concerned at least.

But I think you got the cable thing covered anyways already.

 

[Terraaustralis]

A few comments here to clear some misconceptions:



This is actually not the case. Correct is that a FusionDrive is a hybrid of two drives (like a RAID-0 of some specialised sort) but there is only one single desktop icon named 'Macintosh HD', not two as you suggest. One drive is a SSD, the other is a conventional spinning hard drive. macOS dynamically distributes your data between the two to give you a responsive experience based your use pattern without the costs of a similar sized SSD.

Both a Fusion Drive as well as single internal SSD (or hard drive for that matter) would show exactly the same one icon on the desktop.



I think you're mixing up NAND and DRAM. An SSD without NAND would simply have no capacity to store any data... DRAM (Dynamic Random-Access Memory) which is a fast volatile memory which is used a buffer mostly for cheaper SSDs to temporarily store data which is to be written to the usually slower NAND of budget SSDs. The WD Black SN770 uses Kioxia BiCS5 112L TLC NAND btw.



Be aware that if you ordered an iMac with a single SSD only you won't have the iMac SATA cable and also might likely miss the mounting material. But glueing it in place would certainly be sufficient as no mechanical parts inside. As regards to an SSD, OWC has a bit of a shaky reliability record as well has repeatedly been caught with promises regarding Apple compatibility which proved incorrect, I'd personally use a Samsung like a 870 Evo or Pro (don't opt for a QVO as this has little endurance!). Most Apple SSDs are based on Samsung models anyway so there little compatibility issues as long as SATA SSDs are concerned at least.

But I think you got the cable thing covered anyways already.

Hi mbosse,
I agree with every point you have made. I apologise to all for my confusion with Dram and Nand. Very silly of me. I must be more careful. Thank you for bringing the error to my notice.

It is a long time since I used Fusion and your description of one desk top icon for Fusion was a challenge to my memory. I really cannot remember. I take your word for it. I have learned much from your previous informative posts.

Since my internal SSD’s are one SATA and one NVMe, naturally I have two individual desktop icons and I think I was unconsciously conditioned by that experience. However, Before I got lost in the woods with desktop icons, the question, the real point of the discussion, was to ensure Ruadh has the equipment for a smooth installation. I expected the 2.5" OWC SSD to be nicely mounted on an adapter screwed to the HDD posts.

Of course mwidjaya’s observation is valid. Personally I like equipment mechanically firm, screwed in place and capable of easy removal in future if necessary. In the end it is a personal choice.

 

[mwidjaya]

If this comes from an an authentic Apple source, surely a single SSD cannot be rationally described as a Fusion drive?

The 2TB option from Apple is all flash storage (very expensive option).

You can see from ifixit guide that it is wider than normal blade and loaded with many NANDs.

 

[Terraaustralis]

The 2TB option from Apple is all flash storage (very expensive option).

You can see from ifixit guide that it is wider than normal blade and loaded with many NANDs.

View attachment 2498701

Wow!
Makes the M.2 consumer SSD’s seem very attractive and economical.

 

[mbosse]

Hi mbosse,
I agree with every point you have made. I apologise to all for my confusion with Dram and Nand. Very silly of me. I must be more careful. Thank you for bringing the error to my notice.

It is a long time since I used Fusion and your description of one desk top icon for Fusion was a challenge to my memory. I really cannot remember. I take your word for it. I have learned much from your previous informative posts.

Since my internal SSD’s are one SATA and one NVMe, naturally I have two individual desktop icons and I think I was unconsciously conditioned by that experience. However, Before I got lost in the woods with desktop icons, the question, the real point of the discussion, was to ensure Ruadh has the equipment for a smooth installation. I expected the 2.5" OWC SSD to be nicely mounted on an adapter screwed to the HDD posts.

Of course mwidjaya’s observation is valid. Personally I like equipment mechanically firm, screwed in place and capable of easy removal in future if necessary. In the end it is a personal choice.

All fine - just wanted to make sure the information given is correct. Thanks!

 

[PaulD-UK]

@Terraaustralis "HMB is fast, efficient..."

Host Bus Memory isn't implemented with MacOS, only in Windows etc.
WD apparently get round this by incorporating SRAM in the NVMe controller of their cheaper SSDs instead of using DRAM to cache the data allocation database.

WD/Sandisk have a White Paper:

https://www.thomas-krenn.com/de/wikiDE/images/4/4d/Aup201411211f5.pdf

"Volatile cache is a high speed Random Access Memory (RAM) component that can retain data
as long as power is supplied. SanDisk SSD products use two types of RAM components:
SRAM – Static Random Access Memory, which is very fast, holds data as long as power is
supplied, but is very expensive, with small densities.
DRAM - Dynamic Random Access Memory, which is less expensive, with higher densities. Due
to its internal structure, DRAM cannot hold data for more than a few milliseconds and requires
constant refreshing.
All SanDisk SSD products include the volatile cache component, in varying sizes, using either
SRAM (as part of the SSD controller) or DRAM (as a separated component).

© 2013 SanDisk Corporation. All rights reserved."

 

[Ruadh]

Cannot find the original reference, but memory tells me WD Blue SN570, Black SN770 are listed as Sintech incompatible by both Sintech and WD Black. May also apply to SN580 which is a new modification. Email WD and or Sintech support to confirm status of SN580.

So, the Sintech product page says:

• NOTE:Samsung PM981/950PRO, WD Blue SN570 /SN770 can't work in Macbook, Don't use these SSD.

Product Code:ST-NGFF2013

Whatever that means. Lots of Reddit etc comment that that's no longer true.

Otherwise, they claim compatibility with:

WD:v1, v2 and v3

My guess is that they won't know. The advice on the web is very contradictory, some saying don't use Sintech, with Blue others saying you must.

 

[mwidjaya]

The advice on the web is very contradictory, some saying don't use Sintech, with Blue others saying you must.

It should work.

I have had no issues, even with a generic adapter. AFAIK, the adapter is just a reassignment of the pins.

If any issues, it is coming from the specific nvme.