Blurry icons on MacBook Air M3 with external monitor, same monitor works great on Air M1

[Jugg]

Hello,
I recently purchased a MacBook Air M3 13" and am encountering issues using it with an external display.

For context, I also have a MacBook Air M1 13", which I connect to my Asus VA245 (a standard 24" 1080p monitor) using an HDMI cable and the Apple USB-C to HDMI adapter. It works perfectly—everything looks sharp at 1920 x 1080.

However, when I connect the new Air M3 to the same monitor with the same cable and adapter, the results are noticeably different. The most evident problem is with the dock icons: they appear blurry, both in the dock itself and when doing a CMD+Tab.

The Air M3 runs macOS Sonoma 14.6, while the M1 is still on Big Sur.

I contacted Apple Support, but their advice wasn’t very helpful. They suggested upgrading to macOS Sequoia, which felt like a generic suggestion rather than a real solution. They also recommended taking the computer to an Apple Store, but I suspect that would be a waste of time. I imagine they’ll claim everything works fine on their displays, and even if I bring my monitor or a screenshot, I doubt they’ll see the issue the way I do. (For me, the difference is huge, but I know others might find it minor.)

Does anyone have any ideas? Could upgrading to Sequoia actually help with how things are rendered on this external display? I’ve been hesitant to upgrade because, in my experience, newer macOS versions often worsen things for those of us with high eye sensitivity like me (The support rep did mention that others have complained about this trend).

Thanks in advance for any insights!

 

[Bigwaff]

.. and the resolution of the monitor is definitely 1920x1080 when connected to the M3? You have verified this in Settings > Displays ?

 

[Jugg]

Yes it is.
It looks like the dock is rendered in a different (and wrong) resolution respect to the rest of the screen. Regardless of where the dock is located.

 

[Bigwaff]

If this GPU related then you should be able to take a screenshot and it should capture what you describe. Please share. If not in screenshot then I would try different adapter and HDMI cable.

 

[Jugg]

Hi,
thanks for your reply. Yes, I can see it from a screenshot, even if it's less evident. I don't know if after attaching the files here (which imply resizing and maybe compressing) the difference will still be visible but I personally can see more clear icons with M1 even from the preview here. In particular, the "system settings" icon is pretty evident to me.

M3

M1

 

[HobeSoundDarryl]

I have to think there is a setting difference in play. If it's the same on the Mac end for sure, can you confirm it is the same on the monitor end via monitor menu selections? Be sure the signals the monitor is receiving from each is the SAME.

If there are two inputs on that monitor, have you tried pulling the M1 connection and using the M3 in the same port?

On that Mac end, could you possibly have HiDPI selected for M1 but not for the M3? In other words, identical resolution choices but only M1 is HiDPI? You may have to try an app like BetterDisplay or SwitchResX to "create" a display setting that works for the new combo of M3 with that monitor.

This thread may help. And this Reddit seems to imply the problem is not you, or your cable or your monitor, etc. In fact, there's enough matches for searches for words like "M3 Mac external monitor blurry" to make me think the problem has some breadth. The most common remedy I'm seeing in quick looks around is returning the Mac and getting another.

 

[Jugg]

Hi,
thanks a lot for the info, I will look into the posts tomorrow and get back to you.

I have downloaded BetterDisplay and as far as I see here (screen attached), HiDPI is off (M3). With the M1, I can't find the same long list of information I get on the M3: the BetterDisplay version I am using on M1 is different (older) because it still runs Big Sur, maybe I just don't know where to find that information. However, the "change resolution" menu seems to have many resolutions available and all are prefixed LowDPI so I guess it's off on the M1 as well?

I am not sure how to interpret your last sentence: do you mean that it could be an hardware problem and buying again the same model could fix it? It sounds unlikely to me.

 

[HobeSoundDarryl]

Yes, going by what you’ll find at those links, the remedy at which others seem to eventually arrive is exchanging the Mac. You are going through various steps trying to figure it out. At some point, “blame the product” may be all that’s left.

If yours was the only case, I’d suspect your settings, cable, etc. But when one searches for the same, there are MANY matches in results. Obviously, they are not all using the same external monitor, the same cable, etc. So that starts throwing a little fuel on the fire that it may be that M3 Mac hardware (or macOS bugs).

Since it doesn’t seem to be all M3s, it may just be a bad batch.

One more thought: since you are connecting via HDMI to only HD resolution, would you happen to have an HDTV around the house? If so, take both Macs and connect to it to see if the difference shows on a completely separate "monitor" too. That could rule out/in the monitor itself. That should be an easy test if you have an HDTV around.

Hopefully someone else chimes in with an easier solution.

 

[Jugg]

@HobeSoundDarryl I really have to thank you.
I played with BetterDisplay, enable hiDPI for the external monitor on the M3 and finally icons are rendered just right. Thanks!

I have a couple of questions:

1) Does forcing hiDPI have drawbacks? Lower performances? Heating? If it's totally safe, I am wondering why Apple does not allow to set it for the 1080p resolution, considering the huge improvement in clarity (hiDPI, in MacOS system settings, is available only for lower resolutions: 1024 x 576 and lower)

2) I confirm I don't see any hiDPI option available for the external monitor on the M1, do you know why? And I am also wondering why things were anyway rendered better than on the (lowDPI) M3.

This is my last day available for returning the computer and I am trying to get as much info as possible

Thanks again.

 

[HobeSoundDarryl]

No particular consequence to “forcing HiDPI.” Yes, totally safe.

Perhaps Apple doesn’t offer it direct to make people pay way up for ASD? Apple’s motivations sometimes conflict with what is best for customers. And that “just works” very, VERY well for them. 💰💰💰

M1 drivers may have had it set as default. And then Apple “improved” on that by M3? 😉 Or just another macOS bug(s). Or something else. Instead of classic “just works,” the modern Mac user experience might be tagged as a “workaround” one… as in find your own way in spite of what Apple does… or in spite of bugs left unfixed.

Too bad it took a third party app to make a Mac display as good as possible on your monitor… but glad you got a positive resolution.

 

[Jugg]

Yes it's frustrating how difficult has become to find the right monitor for the right MacBook It should just work ...

As far as I have understood, forcing hiDPI implies additional work for the GPU; I haven't had time to test this adequately but from the very first tests I haven't seen any noticeable difference.

 

[HobeSoundDarryl]

There is additional work for the gpu. In a very general sense, it is rendering for double the resolution it will ultimately display. Think of it like printing at 2X to then view at 1X.

But that’s not a heavy load on the machine. HiDPI is commonly used on all Macs… even to power much greater resolution screens. Nothing to worry about.

Hook a PC to ANY resolution screen and Windows will perfectly scale to work with any of them. Mac is inferior in this part of things as it significantly favors very specific resolutions somewhat connected to HiDPI. The oddball 5K resolution panel costs much more than the commoditized 4K panel, but at a popular size, 5K is what Mac wants. At another size of screen, it’s oddball 6K and in another, oddball 4.5K.

For the Mac UI to appear normal, it wants these oddball panels. Use other choices and the UI can appear too small or too big or blurry. On the other hand, Windows just scales to whatever resolution. It basically “Goldilocks” this part of things.

Yes Mac should be like that too. But oddball choices can be very profitable to sell vs. mainstream options. So we deal with issues like this with Mac. I don’t know of any technological advantage of the Mac approach but fatter margins certainly delight shareholders.

 

[Jugg]

Is there any page in the Apple website mentioning, for each macbook, the optimal resolution for an external monitor?
I remember, not long time ago, that there was the list of supported resolutions, now here I can only see, for the M3:

• Simultaneously supports full native resolution on the built-in display at 1 billion colors and:
• One external display with up to 6K resolution at 60Hz
• Close the MacBook Air lid to use a second external display with up to 5K resolution at 60Hz