crt monitor 60Hz

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crt monitor 60Hz

Post by sandpin »

I use odroid c2 (ubuntu 18.04) with old crt monitor and display at such low refresh rate (60Hz) looks bad. Is it possible to make at least 75Hz in Ubuntu? May be change OS? According to https://wiki.odroid.com/troubleshooting ... esolutions odroid XU4 can 1152×864@75Hz, why not C2?

Thanks!

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Re: crt monitor 60Hz

Post by odroid »

Amlogic S905 internal video output block is very different from Samsung Exynos-5422.

BTW, do you use an HDMI-to-VGA adapter with your old monitor?
What is the maximum native resolution of the monitor?

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Re: crt monitor 60Hz

Post by sandpin »

Yes, I use HDMI-to-VGA adapter, used it with raspberry pi and at 85Hz display looked better, no noticeable flickering. Maximum resolution of the monitor is 1280x1024, the recommended preset operating mode is 1024×768@85Hz.

Coreelec supports vesa modes (https://discourse.coreelec.org/t/is-it- ... 68/2025/19), in particular 1152x864p75hz. Is it possible to apply this patch for c2 in Ubuntu?

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Re: crt monitor 60Hz

Post by odroid »

Ubuntu 18.04 image should support 1280x1024 resolution.
https://github.com/mdrjr/c2_bootini/blo ... ot.ini#L71

But you might need to change the video mode to DVI or VGA from HDMI.
https://github.com/mdrjr/c2_bootini/blo ... ni#L88-L92

Is there any specific reason to use 75Hz instead of 60Hz?
You are the first user who requests it since we launched the C2 almost five years ago.

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Re: crt monitor 60Hz

Post by sandpin »

The reason is simple - flickering, it's bad for eyesight and health. At 75Hz (better 85) I don't see it. So, is it possible to apply the patch from Coreelec in Ubuntu?

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Re: crt monitor 60Hz

Post by odroid »

Is it not that simple to modify the HDMI PLL configuration in Ubuntu kernel.

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