ASUS VG246H and 75Hz

[greenythebeast]

Hi all,

Just bought two ASUS VG246H monitors and am trying to get them to work correctly at 75Hz on Windows 10.

My setup is a Radeon HD 6850, connecting 1 monitor via HDMI and 1 monitor via HDMI->DVI-D (Dual Link) adapter. I enabled FreeSync on both monitors and was able to get 75Hz through Catalyst on the direct HDMI monitor, but not the HDMI->DVI adapter monitor. Also, the 75Hz on the HDMI monitor has frame skipping. Would the pixel clock patcher fix these issues?

Thanks for your help!

[ToastyX]

Radeon HD 6850 does not support FreeSync, but the monitor requires FreeSync to avoid frame skipping at 75 Hz.

[greenythebeast]

(05-25-2023 10:13 PM)ToastyX Wrote:  Radeon HD 6850 does not support FreeSync, but the monitor requires FreeSync to avoid frame skipping at 75 Hz.

OK, thank you for your response. Since I'm using the monitors for office use, I assume I wouldn't really notice the frame skipping if it occurred?

Do you know why only the direct HDMI monitor can get 75Hz, even when both monitors have FreeSync enabled? Does using an HDMI->DVI-D (dual link) adapter disable the possibility for 75Hz?

[ToastyX]

You should use 60 Hz to avoid frame skipping. I would notice it just moving the mouse cursor.

There's no such thing as HDMI to dual-link DVI. Do you mean single-link DVI to HDMI? AMD limits such adapters to 165 MHz pixel clock. The patcher might get around that limit, but it won't fix the frame skipping.

[greenythebeast]

(05-28-2023 01:19 AM)ToastyX Wrote:  You should use 60 Hz to avoid frame skipping. I would notice it just moving the mouse cursor.

There's no such thing as HDMI to dual-link DVI. Do you mean single-link DVI to HDMI? AMD limits such adapters to 165 MHz pixel clock. The patcher might get around that limit, but it won't fix the frame skipping.

I set the monitor to 75Hz and ran the testufo Frame Skipping test (https://testufo.com/frameskipping) and it passed with no issues. So I think having it at 75Hz is OK.

I did some research and you are correct, there is no HDMI -> dual-link DVI adapter. I saw that the adapter had 24 pins, so I assumed that it was dual-link. My 6850 has 2 DVI ports, 1 HDMI port, and 1 DP port. All 3 of my monitors are HDMI/VGA only, so it looks like I'll only be able to get 2 of them to 75Hz, since I can't find an MST Hub that supports 1080p/75Hz over HDMI. Unless you have any other ideas? Thanks for your help!

[ToastyX]

If the monitor can do 75 Hz without needing FreeSync, then you can try using CRU to edit the detailed resolution for 1920x1080 @ 75 Hz to use "Exact reduced" timing, which will be exactly 165 MHz pixel clock, so it won't need the patcher.

[greenythebeast]

(06-02-2023 01:33 AM)ToastyX Wrote:  If the monitor can do 75 Hz without needing FreeSync, then you can try using CRU to edit the detailed resolution for 1920x1080 @ 75 Hz to use "Exact reduced" timing, which will be exactly 165 MHz pixel clock, so it won't need the patcher.

Unfortunately, I can't get it to 75Hz without enabling FreeSync. I think I'm just going to use 60Hz on all three monitors. There isn't too much of a difference between 60 and 75 to my eyes. Thanks for your help!

[greenythebeast]

(05-28-2023 01:19 AM)ToastyX Wrote:  You should use 60 Hz to avoid frame skipping. I would notice it just moving the mouse cursor.

There's no such thing as HDMI to dual-link DVI. Do you mean single-link DVI to HDMI? AMD limits such adapters to 165 MHz pixel clock. The patcher might get around that limit, but it won't fix the frame skipping.

Hey,

You obviously are more knowledgeable about this stuff than I, so I'm hoping you can answer a quick question. How does one avoid frame skipping on higher refresh rates? Do I need to get a better graphics card, better monitors, or is it unavoidable?

[ToastyX]

Frame skipping is a monitor limitation, not a performance issue. I'm not sure about this particular model, but I remember certain 1920x1080 @ 75 Hz FreeSync monitors would skip frames at anything other than 60 Hz if FreeSync wasn't enabled. This isn't common with other FreeSync monitors.