What RAM to buy for iMac20,1

[Michaelt972]

I am a new iMac user, and have owned a macbook pro for several months.

I just purchased the 2020 27" iMac, model 20,1

I purchased it with only 8 gigs of ram because I didn't want to wait a month for Apple customization.

It's my understanding the 27" iMac20 can have the RAM upgraded by user.

I'd like to know what RAM to purchase.

I've checked Amazon, of course, and the reviews for certain RAM modules don't look good--people claiming added RAM freezes the computer, with complaints saying that added RAM "bricked" the iMAC.

I want to make sure purchased RAM works in my iMAC.

I'm not looking for the cheapest RAM.

I'm looking for RAM that works.

Any suggestions greatly appreciated.
Thank you in advance.
Michael.

 

[SRQrws]

I've upgraded multiple iMacs with Crucial memory (crucial.com). They have 8,16,32 and 64GB kits available and you can purchase either directly online from them or they have a "where to buy" link. Lately, the only issue is sometimes they have stock-outs so you may have to wait a week or so.

 

[wilberforce]

Best recommendation is Crucial, this is what I use:

Crucial 32GB Kit (16GBx2) DDR4 2666 MT/s (PC4-21300) CL19 DR x8 SODIMM 260-Pin for Mac - CT2K16G4S266M

CT2K16G4S266M is a 32GB Kit consisting of (2) 16GB Dual Ranked DDR4 SODIMM modules that operates at speeds up to 2666 MT/s and has a CL19 latency. It is an Unbuffered SODIMM. It conforms to the industry standard DDR4 SODIMM layout of 260 pins and is compatible with systems that take DDR4 2666MT/s...

www.amazon.com

Crucial RAM 64GB Kit (2x32GB) DDR4 2666 MHz CL19 Memory for Mac CT2K32G4S266M, Multicolor

CT2K32G4S266M is a 64GB Kit consisting of (2) 32GB DDR4 SODIMM for Mac that operates at speeds up to 2666 MT/s and has a CL19 latency. It is an Unbuffered SODIMM. It conforms to the industry standard DDR4 SODIMM layout of 260 pins and is compatible with systems that take DDR4 2666 MT/s SODIMM mem...

www.amazon.com

Pick either the 32GB kit or the 64GB kit. Verify the option you selected is 2666 MT/s (not 2400 MT/s)

Toss your 8GB Apple RAM

 

[LaurentR2D2]

Best recommendation is Crucial, this is what I use:

Crucial 32GB Kit (16GBx2) DDR4 2666 MT/s (PC4-21300) CL19 DR x8 SODIMM 260-Pin for Mac - CT2K16G4S266M

CT2K16G4S266M is a 32GB Kit consisting of (2) 16GB Dual Ranked DDR4 SODIMM modules that operates at speeds up to 2666 MT/s and has a CL19 latency. It is an Unbuffered SODIMM. It conforms to the industry standard DDR4 SODIMM layout of 260 pins and is compatible with systems that take DDR4 2666MT/s...

www.amazon.com

Crucial RAM 64GB Kit (2x32GB) DDR4 2666 MHz CL19 Memory for Mac CT2K32G4S266M, Multicolor

CT2K32G4S266M is a 64GB Kit consisting of (2) 32GB DDR4 SODIMM for Mac that operates at speeds up to 2666 MT/s and has a CL19 latency. It is an Unbuffered SODIMM. It conforms to the industry standard DDR4 SODIMM layout of 260 pins and is compatible with systems that take DDR4 2666 MT/s SODIMM mem...

www.amazon.com

Pick either the 32GB kit or the 64GB kit. Verify the option you selected is 2666 MT/s (not 2400 MT/s)

Toss your 8GB Apple RAM

Hello. Will this RAM work in an iMac 2020 20,2 ? Also, how does it works with Apple warranty ? From what I remember, in case of problem with the iMac, they ask to put back their RAM if you want them to check your computer ?

 

[costica1234]

Hello. Will this RAM work in an iMac 2020 20,2 ?

I have the 20,2 model with 4 modules of 16 GB from Crucial and it works perfectly. Note that the 20,2 identifier refers to machines having the higher-end GPUs, namely 5700 or 5700XT (link).

 

[LaurentR2D2]

I have the 20,2 model with 4 modules of 16 GB from Crucial and it works perfectly. Note that the 20,2 identifier refers to machines having the higher-end GPUs, namely 5700 or 5700XT (link).

Fine. I've taken the 32gb kit. Thank you 🙂

 

[tonysabbath]

Like others have said Crucial memory is fine. They even make slightly more expensive "made for Mac" memory too.

I brought the iMac20,2 a few months ago and messed around with memory. Do not mix the Apple ram with different capacities e.g do not mix 4GB modules with 8GB modules. I ended up taking out the 2x Apple 4GB modules and used 4x Crucial 8GB 2666MHz instead.

 

[LaurentR2D2]

Toss your 8GB Apple RAM

Last question. Why do you advise to toss the 8gb Apple RAM ? I've been to fast. The answer is just above

 

[LaurentR2D2]

Like others have said Crucial memory is fine. They even make slightly more expensive "made for Mac" memory too.

I brought the iMac20,2 a few months ago and messed around with memory. Do not mix the Apple ram with different capacities e.g do not mix 4GB modules with 8GB modules. I ended up taking out the 2x Apple 4GB modules and used 4x Crucial 8GB 2666MHz instead.

Why 4 8gb modules. You think it's better than 2 16 gb modules ?

 

[costica1234]

Why 4 8gb modules. You think it's better than 2 16 gb modules ?

It shouldn't make a difference, but with 2x16 GB you have the ability to add another 32 GB down the road. I initially bought 2x16 GB and added another set later because I didn't want my iMac to write stuff to the SSD when running some programs consuming 30GB+ of memory.

 

[wilberforce]

Last question. Why do you advise to toss the 8gb Apple RAM ? I've been to fast. The answer is just above

Mixing sizes of sticks on the 2020 iMac will run, but the speed will drop to 2133 MT/s (or lose dual channel, depending on what order you install them). OP just asked for what ram to use, not for the explanation why, so I did not explain. (But happy to do so.)

 

[LaurentR2D2]

Thank you. I've installed my RAM today. Everything seems to be fine. Pressure is between 8 and 12%. I've put the modules at the same place than the original one, and I see in About my Mac that they are in Slot 3 and 4. Is it a problem that they are not in Slot 1 and 2 ?

 

[wilberforce]

Thank you. I've installed my RAM today. Everything seems to be fine. Pressure is between 8 and 12%. I've put the modules at the same place than the original one, and I see in About my Mac that they are in Slot 3 and 4. Is it a problem that they are not in Slot 1 and 2 ?

I suggest instead put them in slots 2 and 4 (or slots 1 and 3), where slot 1 is at top, else you do not have dual channel. Without dual channel, the ram transfer speed is effectively halved.
To get full dual channel you need to have the same amount of RAM in channel A and in channel B.
You can check for yourself by running Novabench ram speed test. You should get about 29000 if configured correctly

 

[LaurentR2D2]

I suggest instead put them in slots 2 and 4 (or slots 1 and 3), where slot 1 is at top, else you do not have dual channel. Without dual channel, the ram transfer speed is effectively halved.
To get full dual channel you need to have the same amount of RAM in channel A and in channel B.
You can check for yourself by running Novabench ram speed test. You should get about 29000 if configured correctly

I've put the modules in slots 1 and 3. Before doing that, Novabench showed me a score of 286 with RAM speed at 19232MB/s and now I get a score of 318 with a RAM speed of 28299 MB/s. Much better. Thank you . I've also noticed that CPU, GPU and Disk score were better too. CPU : 1948 instead of 1874. GPU 919 instead of 734, and Disk Score, 177 instead of 175. Does RAM score have en effect on CPU and GPU score ?

 

[Late2011MBPFan]

Is there any difference between the Made for Mac Crucial and the universal besides branding? Does it go through additional compatibility testing?

 

[tonysabbath]

Is there any difference between the Made for Mac Crucial and the universal besides branding? Does it go through additional compatibility testing?

All I know is that I originally brought a 16GB Crucial Kit and it worked but the System Profiler had some info missing. I exchanged them for Crucial's "Mac" edition which had the same specs and looked identical and the System Profiler showed all info. Weird but there you go.