Problems with my M1 Mac Mini (Ram-CPU Usage, HDR, Bluetooth)

[JippaLippa]

Hello.

I have recently purchased a mac mini M1 (with 16 GB of ram and 256 GB of SSD); alongside the M1 I purchased a 4K display, specifically the Benq PD2700U 4K.

Attached to the M1 I have these things:

• MacOS 11.1 (latest update)
• USB 3.1: Focusrite Scarlett Solo Audio Interface (working)
• USB 3.1: sata adapter for external SSD (working)
• Thunderbolt: Minix USB HUB (working)
• Thunderbolt: Nothing Yet
• Ethernet: Ethernet Cable (working)
• HDMI: Benq DIsplay 4K HDR PD2700U 27" (some problems)
• Bluetooth 1: Magic Kkeyboard with numpad (working)
• Bluetooth 2: Apple Magic Mouse 2 (some problems)

Since I have set up the computer, though, I have been noticing some weird behaviour, and I'd like to determine (with your kind help) if the mac or the display are broken, or if some of these are known bugs that have a hope of being fixed with an update.
I'll go in orther, with appropriate documentation for each.

Ram Usage:
Being a power user I have gotten the 16GB model, but upon watching many reviews I noticed the computer seems to work flawlessly even with the 8GB model.
That said I started noticing huge levels or ram usage in teh computer, even when simply at dle it show around 5GB of consumption:

Those figures were reported biw iStatistica, but upon looking at the activity monitor, this is the situation with just 2 tabs opened in firefox /the M1 optimized version).
I'm not sure this is ok...so people with the 8GB version can't have 2 tabs opened of firefox without maxing the ram? Doesn't sound right..
Anyway I have noticed the ram never going below 4.20 GB, not even when at idle.

CPU USAGE:

I noticed the CPU going up around 50% with some light use (scrolling some web pages with imessage open and apple music) and so on.
This is not in any alarm territory, but still...

HDR:

This is where things get murky...
In this set-up there's definitely something wrong with the HDR, as by having the diplay connected via the HDMI port, the view with HDR (both with some premium expensive cables I bought and the cheap one the cmonitor came with) is horrible...
The colours become extremely washed out in the UI, and when I see HDR content on youtube the colours are just wrong, with skin tones losing detail and becoming very saturated magentas, orange colours becoming so dense thet they are oainful to watch and shadows becoming almost grey.
Also there's an intense color fringing effect (or chromatic aberration around the text) which is extremely annoying anb not present if I disable the HDR in the settings.
Considering the monitor fails to connect to my windows PC (That I'm sure wotks fine) and the fact it makes an unnerving BZZZZ sound, I think it might be the display that's broken, but having experienced all the other issues I'm not sure abou the mac too.
One time when I was watching an HDR video on youtube, the computer crashed with this message:

Side note:
I have noticed the HDR doesn't have any colour fringing on Safari...perhaps I'll switch

I wasn't able to make the computer crash again with HDR disabled...not even in intense testing envirnoments.
If we look at the benchmarks the computer seems to be fine:

BLUETOOTH:
Not too much of a big deal, but sometimes the mouse slows down a little, despite being very closed to the computer.
That said I kinda know of this problem to be a classic one with macs...

I need your help to evaluate all of the above.
Are the problems with the mac knwn issues that have ahope of being fixed? Is that ram usage normal? Are there HDR issues with these M1s? Do you think the display is broken (as I do think).
Do you have any tests to suggest?

Anyway I understand this was quite a long post, therefore I'd like to express my complete gratitude to everyone that'll be kind enough to help me with these issues.
I have saved up for ages to purchase this setup and I won't be able to obtain anything similar for a very long time.

Cheers, and happy new year!

 

[CheesePuff]

macOS intelligently uses RAM, do not worry about it unless your memory pressure is always showing yellow (or red). To be honest I would not even display that metric so you don't obsess over it, only if you notice the machine being slower then usual check the pressure.

 

[JippaLippa]

macOS intelligently uses RAM, do not worry about it unless your memory pressure is always showing yellow (or red). To be honest I would not even display that metric so you don't obsess over it, only if you notice the machine being slower then usual check the pressure.

Thank you.
Any comment on the rest?

 

[CheesePuff]

Thank you.
Any comment on the rest?

I don't have a M1 Mac mini but I have read on here and other forums about numerous people having Bluetooth issues exactly as you're describing (here is an article on it https://9to5mac.com/2020/11/24/user...oth-connectivity-issues-with-new-m1-mac-mini/)

The article doesn't mention it but I do recall someone saying it was interference caused by the material of their desk the mini was on, and to try placing the Mac mini up vertically rather then horizontally to see if that causes it to go away (btw I have used the Magic Mouse 2 on a 2015 5K iMac, 2020 5k iMac and numerous MacBook Pro models and never once got it to stutter so it should always be smooth for you)

 

[joevt]

4K 60Hz HDR requires 10bpc at least, which means it's using chroma sub sampling because HDMI 2.0 only has enough bandwidth for 4K 60Hz 8bpc without chroma sub sampling.

Chroma Subsampling: 4:4:4 vs 4:2:2 vs 4:2:0

What is Chroma Subsampling and where is this visible? Chroma subsampling is a type of compression that reduces the color information in a signal in favor of luminance data.

www.rtings.com

It shouldn't be a problem for grayscale text though.
Can you show a picture of the color fringing effect?
I don't know a method to show the pixel format of the output signal for the display.

 

[JippaLippa]

4K 60Hz HDR requires 10bpc at least, which means it's using chroma sub sampling because HDMI 2.0 only has enough bandwidth for 4K 60Hz 8bpc without chroma sub sampling.

Chroma Subsampling: 4:4:4 vs 4:2:2 vs 4:2:0

What is Chroma Subsampling and where is this visible? Chroma subsampling is a type of compression that reduces the color information in a signal in favor of luminance data.

www.rtings.com

It shouldn't be a problem for grayscale text though.
Can you show a picture of the color fringing effect?
I don't know a method to show the pixel format of the output signal for the display.

It's connected via an expensive HDMI 2.1 cable., but I noticed the M1 mac only has an HDMI 2.0 port.
Could I have the signal adapted from thunderbolt to use 10-bit? I don't mind sacrificing a thunderbolt port.

I found this adapter in my country on amazon: https://www.amazon.it/CABLEDECONN-D...+to+DisplayPort+Adapter&qid=1609641943&sr=8-3

It shuld work as I guess Display Port 1.4 supports 10bit and upon reading other reports of people with 10-bit benq displays, the adapter (if of decent quality) works.

Thanks

 

[glindon]

CPU usage is reported different from say Windows. If all the cores were being used activity monitor would say 800% for a process. So 50% is just 1 low power core barely being used. From what I’ve read MacOS will almost exclusively use the lower powered cores unless an app calls for the high powered cores. Things like networking, downloading files, rendering the UI for scrolling, installing apps, playing videos, disk access, etc. never use the faster cores.

 

[joevt]

It's connected via an expensive HDMI 2.1 cable., but I noticed the M1 mac only has an HDMI 2.0 port.
Could I have the signal adapted from thunderbolt to use 10-bit? I don't mind sacrificing a thunderbolt port.

I found this adapter in my country on amazon: https://www.amazon.it/CABLEDECONN-D...+to+DisplayPort+Adapter&qid=1609641943&sr=8-3

It shuld work as I guess Display Port 1.4 supports 10bit and upon reading other reports of people with 10-bit benq displays, the adapter (if of decent quality) works.

Yes, the BenQ PD2700U has DisplayPort 1.4 input so you should use that instead of HDMI 2.0a input.