Very limited resolutions for second monitor

Using HomeBrew <http://brew.sh> you can install avibrazil-rdm which will give you access to a bunch of other resolutions.

But first try the Option-Click Scaled. That often gives you want you want.

There is a little free app called Display Menu you can download from the App Store

which when downloaded and opened will give you a monitor icon in the menubar

where you can select the resolution for your monitors.

I connected a Acer 1080p monitor via Apple's Thunderbolt 3 HDMI adapter and an HDMI cable to my Late 2016 15" Macbook Pro w/Touchbar

I Option-Clicked on the Scaled button, and these are the higher resolutions offered by Apple

I launched RDM (installed via "brew install avibrazil-rdm", these are all the size options I saw for the Acer monitor

Here is the Apple specified 1080p screen

Here is the 2048x1260 screen

Here is the 3840x2160 screen

Here is the 4096x2304 screen

Here is the 7680x4320 screen (mostly useless as it was so tiny (the 4096x2304 and the 3840x2160 sizes were not very useful either)

So if your monitor will not support these sizes, it is not Apple's fault. It is either

• Your monitor
• Your TB3-HDMI adapter
• Your HDMI cable

I just figured this was the way that it was. Then, I had to test something on my Windows laptop and I discovered that it does 2560 x 1600 by default. Looks pretty good on that too.

Ah. And there's the main difference. As an example, an older Sony 40" HD TV was had was one of the first 1080p (progressive) models. Pretty much everything before that was 1080i (interlaced). The screen itself though was not 1920 x 1080. The actual dot pitch was much higher than that.

That's what's happening. macOS is strictly adhering to what the monitor's firmware is saying the top resolution is (1920 x 1080) and ignoring the panel's actual specs. Windows is ignoring the firmware's reported dimension of 1920 x 1080 and is detecting the panel's actual pixel dimensions.

This is what the earlier responses were hoping you could find by Option+clicking directly on the word "Scaled". But it appears the OS is ignoring anything above 1920 x 1080.

I don't know why monitor manufacturers do that. That is, why do they limit the user to a resolution smaller than what the panel itself is capable of? If the real resolution of the panel is 2560 x 1600, then put that in the firmware as a supported size.

Hold Alt key when selecting Scaled

Out of curiosity, am I missing the name of the monitor vendor and of the model in this thread, or has it been omitted? I see 27B1 in one image, which is close to an AOC 27B1H, though that’s 1920 by 1080 per the specs, which is what you’re reporting. And have you checked with the monitor vendor (AOC?) for firmware updates? Firmware issues and down-revision firmware are a common source of “fun” with newer displays.

Kurt Lang wrote:

I just wish the Mac would be less rigid about it. Let me try some new display sizes even if they look like crap, eh?

Agreed, but I would bet Apple is just trying not to run afoul of another company's rules. There's likely some kind of legal issue involved with bypassing the "official" resolutions.

Bad refresh rates and bad scan rates used to damage display hardware. CRTs with analog connections were fussy about this, and one graphics driver development team I knew well used to fry a monitor on occasion. The current digital links tend to either work, or they don’t. Apple has never been about working badly with random hardware gear, as that feature has already widely available in the market. And the complaint here is not with Apple, it’s with the monitor vendor. Who probably decided to cost-reduce and spec-reduce this monitor further than the purchaser might have preferred.

I’m not sure who you think is toeing which line here nor why, but we’re not Apple folks. We’re other users.

The AOC 27B1H is advertised as a 1920 by 1080 display. Which is what you indicate you’re getting.

Do you have a different model or variant of this monitor? Check those specs for what’s supported.

As for monitor firmware updates, check with the monitor vendor support site and support folks.

Some vendors and models have firmware that can be updated—some LG monitors, for example—and others do not.

What Microsoft Windows is doing with display resolutions and refresh rates, I really don’t know.

What happens when you select “native” / “default for the display” for the display?

Kurt Lang wrote:

I don't know why monitor manufacturers do that. That is, why do they limit the user to a resolution smaller than what the panel itself is capable of? If the real resolution of the panel is 2560 x 1600, then put that in the firmware as a supported size.

Product positioning. They’re selling a range of products at a range of prices, and using common parts where they can.

I am running Mojave

sudo xcode-select --install

gcc --version

Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/c++/4.2.1

Apple clang version 11.0.0 (clang-1100.0.33.17)

Target: x86_64-apple-darwin18.7.0

Thread model: posix

InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin