USB-C : Lower image quality when in 144Hz


I’m using a 2021 Apple Silicon MacBook Pro on Monterey, connected via USB-C to the 144Hz 4K Eve Spectrum. It’s currently running firmware 105.

When switching to 144Hz, the image quality decreases noticeably: color slightly bleeds, especially around very colored icons, or colored text.
When enabling HDR on top of 144Hz, the issue gets much more visible.

Is this expected? Is this chroma subsampling, or some other form of lossy compression, that’s necessary because of limited bandwidth somewhere? Or is it a glitch, or a limitation that could hopefully be resolved with a firmware update?

Based on the description, it’s chroma subsampling.

Whether it’s a color problem or not, how can we solve the problem of not being clear? Is it a line change? Or will the subsequent firmware be upgraded? Many people use MacOS. In China, many people use our monitors. This problem can be solved by other brands of monitors. Can we solve it through firmware update???

Some users reported that v107 firmware solved the issue. You can read more about that here.
Hope this has provided some assistance with your issue :slight_smile:

I have updated 107 firmware. On MacOS, as before, the image quality is obviously degraded. You can try it yourself, especially 144hz

Without chroma subsampling or DSC 120hz would be the highest available refresh rate. Chroma subsampling or DSC is needed to reach 144hz.

Well, thank you for your reply, thank you

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There’s a potential issue with DisplayPort over USB-C, which can cause the OS to reduce the amount of video bandwidth used even though there’s plenty of bandwidth available. This has been reported back to the company that make the scaler chip, and they’re investigating the issue and any potential fix.

If it is indeed a bug, it should be something that a firmware update can help to fix.