Mixed memory size - Mac Mini 2018

[Alan Browne]

I have a Mac Mini at work with 2 x 4 GB DDR4 / 2667 MHz

They are labeled as Bank 0 / Channel A and
. Bank 2 / Channel B

Does this exclude mixing memory sizes? eg: replacing a 4 GB RAM with an
8 or 16 for a total of 12 or 20? Or do I go 2x8 for a total of 16GB?

Reason: it's an i3 and while it's generally fine, when I add a second
display and I have a lot going on including a VM with Windows, it tends
to bog down ... available memory is under 1 GB, memory pressure is in
the red and there's considerable swapping going on....

- side note - up to 1.5 GB is shared with the graphics.

https://www.dropbox.com/s/voq991puvb2amop/mempress.png

[Alan Baker]

<https://everymac.com/>

Specifically:

<https://everymac.com/systems/apple/mac_mini/index-macmini.html>

[Wade Garrett]

Don't know about a mini but I had a 2009 iMac that came with two 4 GB
memory sticks installed and two empty slots. I added two name brand 2 GB
sticks with the same specs in the empty slots and all worked fine.

When I ran First Aid in Disk Utility though, it showed 12 GB of memory
but an "error" message saying that the two added sticks were not
official Apple memory.

I had occasion to take the Mac to the local Apple store to deal with a
screen issue and the so-called Genius Bar guy looking at it pitched a
fit that I had installed memory not purchased from Apple. He also told
me the screen problem was apparently caused by water damage.

I explained to him that whenever I took my iMac into the shower with me,
I was very careful to first cover it in commercial grade Saran Wrap then
put it in a big plastic bag sealed with a clothespin. He said that
voided the warranty!!

After I got rid of that humorless nitwit, his supervisor came over and
quickly diagnosed/resolved the screen issue. He said the added Crucial
brand memory sticks were fine and to ignore Apple's FUD (Fear,
Uncertainty, Doubt) message inserted by the marketing people.

--
Why is it that the people who want more government control over your
life are the same ones who want you to be disarmed?

[Lewis]

In message <cIN6I.8158$Ho7....@fx11.iad> Alan Browne <Blac...@entropy.ultimateorg> wrote:

> I have a Mac Mini at work with 2 x 4 GB DDR4 / 2667 MHz

> They are labeled as Bank 0 / Channel A and
> . Bank 2 / Channel B

> Does this exclude mixing memory sizes? eg: replacing a 4 GB RAM with an
> 8 or 16 for a total of 12 or 20? Or do I go 2x8 for a total of 16GB?

Depends on the model of mini. I think if it can take 8 it can take 16,
but look it up on MacTracker?

I would, but I cannot right now.


--
The most perfidious way of harming a cause consists of defending it
deliberately with faulty arguments.

[Alan Browne]

On 2021-03-24 18:40, Wade Garrett wrote:
> On 3/24/21 4:56 PM, Alan Browne wrote:
>>
>> I have a Mac Mini at work with 2 x 4 GB DDR4 / 2667 MHz

>

> I had occasion to take the Mac to the local Apple store to deal with a
> screen issue and the so-called Genius Bar guy looking at it pitched a
> fit that I had installed memory not purchased from Apple. He also told
> me the screen problem was apparently caused by water damage.

I was chatting with a an Apple guy about adding mem to a 2008 and he
didn't care that I saved money by buying from OWC or the other one...

>
> I explained to him that whenever I took my iMac into the shower with me,
> I was very careful to first cover it in commercial grade Saran Wrap then
> put it in a big plastic bag sealed with a clothespin. He said that
> voided the warranty!!

You betcha. A clothespin is simply not sufficient. Need a potato bag
chip clip.

>
> After I got rid of that humorless nitwit, his supervisor came over and
> quickly diagnosed/resolved the screen issue. He said the added Crucial
> brand memory sticks were fine and to ignore Apple's FUD (Fear,
> Uncertainty, Doubt) message inserted by the marketing people.

Yep. No issue there... (I had added 4 GB to a 2 GB iMac (2007?) when
the spec was 4 GB. But it worked fine).

I do have mixed mem on this home iMac (original 8 on 2 slots plus 16 on
the 2 other slots).


--
"...there are many humorous things in this world; among them the white
man's notion that he is less savage than the other savages."
-Samuel Clemens

[Alan Browne]

On 2021-03-24 18:55, Lewis wrote:
> In message <cIN6I.8158$Ho7....@fx11.iad> Alan Browne <Blac...@entropy.ultimateorg> wrote:
>
>> I have a Mac Mini at work with 2 x 4 GB DDR4 / 2667 MHz
>
>> They are labeled as Bank 0 / Channel A and
>> . Bank 2 / Channel B
>
>> Does this exclude mixing memory sizes? eg: replacing a 4 GB RAM with an
>> 8 or 16 for a total of 12 or 20? Or do I go 2x8 for a total of 16GB?
>
> Depends on the model of mini. I think if it can take 8 it can take 16,
> but look it up on MacTracker?
>
> I would, but I cannot right now.

First thing I looked at was MacTracker. No indication for or against
mixed sizes. If it were 4 slots (2 banks of 2) I wouldn't hesitate.
But the odd labeling above has me doubting. I'll probably end up
throwing 2 x 8 at it. Company money.

[Andreas Rutishauser]

In article <s3g9d9$i0e$2...@dont-email.me>,

I do not ee any mention of mixing or not of memory modules

<https://everymac.com/systems/apple/mac_mini/specs/mac-mini-core-i3-3.6-l
ate-2018-specs.html>

Cheers
Andreas

[JF Mezei]

Memory size isn't the only thing.
There is also whether it is ECC or not,
whether Registered or unbuffered. (don't think this applies to DDR4)


My trash can had come with unbuffered and I couldn't find unbuffered RAM
that fit the rest of specs so I had to ditcth the RAM and populate from
scratch with new registered ones.



Not sure I have the right CPU, biut it matches the generic Specs Apple
gives for 2018 Mini (3.6hgz with 6MB cache).

> https://www.intel.com/content/www/us/en/products/sku/126688/intel-core-i38100-processor-6m-cache-3-60-ghz/specifications.html


sysctl -n machdep.cpu.brand_string

The above will give you your exact CPU model number, not the "pretty"
thing the Mac GUI tells you. With that you can lookup the exact specs on
the Intel site. (man sysctl to get list of variables you can list).

Example for my trash can:

To get memory specs:
system_profiler SPMemoryDataType
Memory:

Memory Slots:

ECC: Enabled
Upgradeable Memory: Yes

DIMM1:

Size: 16 GB
Type: DDR3 ECC
Speed: 1866 MHz
Status: OK
Manufacturer: 0x0000
Part Number: -
Serial Number: 0x00004B43

The information for each DIMM is the same as shown by System
Profiler/System Report app. But the top ones (ECC enable, and upgradable
yes/no) are not shows in the GUI.

(Note, in my case, the software doesn't show if registered or
unbuffered, it's on the label or look up model number on Internet)
But as I said before, appears to not be an issue with DDR4.

Assuming I got the right CPU for your 2018 Mini, you need DDR4-2400 with
or without ECC .

Since Apple states memory is not upgradable, they won't give you the
specs, so you have to find out what you hyave and what the Intel specs
are for that CPU.

[Lewis]

Very few Macs require matched pairs of RAM, and I think none of the
minis.

However, not knowing which mini it is makes the question impossible to
answer.

There are models of the mini with a 8GB maximum (the 2009-2010). All the
newer minis can take 16. The 2018 can take 64.

None of them require matched pairs, but the 2018 requires Apple service
to upgrade the RAM and they will only upgrade matched pairs.

--
"Are you pondering what I'm pondering?"
"I think so, Brain, you'd think [Lyndon Johnsonwould] have left room
for baby-kissing, wouldn't you?"

[Alan Browne]

On 2021-03-25 05:51, Lewis wrote:
> In message <andreas-F2AAC8...@news.individual.de> Andreas Rutishauser <and...@macandreas.ch> wrote:
>> In article <s3g9d9$i0e$2...@dont-email.me>,
>> Alan Baker <notony...@no.no.no.no> wrote:
>
>>> On 2021-03-24 1:56 p.m., Alan Browne wrote:
>>>>
>>>> I have a Mac Mini at work with 2 x 4 GB DDR4 / 2667 MHz
>>>>
>>>> They are labeled as Bank 0 / Channel A and
>>>> .                   Bank 2 / Channel B
>>>>
>>>> Does this exclude mixing memory sizes?  eg: replacing a 4 GB RAM with an
>>>> 8 or 16 for a total of 12 or 20?  Or do I go 2x8 for a total of 16GB?
>>>>
>>>> Reason: it's an i3 and while it's generally fine, when I add a second
>>>> display and I have a lot going on including a VM with Windows, it tends
>>>> to bog down ... available memory is under 1 GB, memory pressure is in
>>>> the red and there's considerable swapping going on....
>>>>
>>>> - side note - up to 1.5 GB is shared with the graphics.
>>>>
>>>> https://www.dropbox.com/s/voq991puvb2amop/mempress.png
>>>
>>> <https://everymac.com/>
>>>
>>> Specifically:
>>>
>>> <https://everymac.com/systems/apple/mac_mini/index-macmini.html>
>
>> I do not ee any mention of mixing or not of memory modules
>
> Very few Macs require matched pairs of RAM, and I think none of the
> minis.
>
> However, not knowing which mini it is makes the question impossible to
> answer.

Subject line: "Mac Mini 2018"

>
> There are models of the mini with a 8GB maximum (the 2009-2010). All the
> newer minis can take 16. The 2018 can take 64.
>
> None of them require matched pairs, but the 2018 requires Apple service
> to upgrade the RAM and they will only upgrade matched pairs.

And yes, users can upgrade the memory regardless of Apple's desires to
charge more for it...

Where do you see the 2018 doesn't require matched sizes?

[Lewis]

If you do not put relevant information in the text of the message people
are not going to read it, but we have done this before and I'm not doing
it again.

>> There are models of the mini with a 8GB maximum (the 2009-2010). All the
>> newer minis can take 16. The 2018 can take 64.
>>
>> None of them require matched pairs, but the 2018 requires Apple service
>> to upgrade the RAM and they will only upgrade matched pairs.

> And yes, users can upgrade the memory regardless of Apple's desires to
> charge more for it...

> Where do you see the 2018 doesn't require matched sizes?

that is not the question, the question is where do you see that it DOES?

--
"Are you pondering what I'm pondering?"

Pinky: (holding one of the pointy pieces from Sorry! and the bottle
of Slick 'n Slide) I think so, Br...
Brain: [shuts Pinky's mouth] No, on second thought, don’t tell me...
I don't think they allow that in a book with the Comics Code.

[JF Mezei]

On 2021-03-25 07:48, Alan Browne wrote:

> Where do you see the 2018 doesn't require matched sizes?

Intel has good article on the issue.

> https://www.intel.ca/content/www/ca/en/support/articles/000005657/boards-and-kits.html


the i3 has 2 memory channels, the type of memory and how you arrange it
disctates whether it will work in single channel mode (less throughput)
or dual channel mode (higher throughput). But having only 2 slots kind
limits how you can arrange 2 RAM sticks :-)

It mentions that some firmware will warn of less performance at POST if
mismatched sizes causes it to go into single channel mode but otherwise
will work.

The system will use the clock rate of the slowest DIMM and RAM will work
at lower clock rate than its is marketed at.

[Alan Browne]

Strange attitude. Oh, it's Lewis. Right.

>
>>> There are models of the mini with a 8GB maximum (the 2009-2010). All the
>>> newer minis can take 16. The 2018 can take 64.
>>>
>>> None of them require matched pairs, but the 2018 requires Apple service
>>> to upgrade the RAM and they will only upgrade matched pairs.
>
>> And yes, users can upgrade the memory regardless of Apple's desires to
>> charge more for it...
>
>> Where do you see the 2018 doesn't require matched sizes?
>
> that is not the question, the question is where do you see that it DOES?

Ambiguous.

[Alan Browne]

Good article. Thanks. IAC I've ordered 2 x 8 to replace the 2 x 4's...

[Fishrrman]

On 3/24/21 4:56 PM, Alan Browne wrote:
>

> Does this exclude mixing memory sizes?  eg: replacing a 4 GB
> RAM with an 8 or 16 for a total of 12 or 20?  Or do I go 2x8
> for a total of 16GB?

Before I got my 2018 Mini, I used a 2012 Mini with 2gb in
one DIMM slot, and 8gb in the other.

It worked fine, and if there was any "slowdown" due to the
dissimilar DIMM sizes, I never noticed them.

[Alan Browne]

Yep - I used to run my old iMac on 2 + 4 (or rather [1+1] + [2+2]).

My current iMac is 8 + 16 ([4+4] + ...)

It just seemed ambiguous when there were 2 slots v 4. Paranoid I guess.

IAC: 2 x 16 is in and ...see my other post today...