Mismatched refresh rates issue.

Question

Hi, when my main display is set to my 4k 60hz monitor my 1080p 165hz monitor displays at 60hz even though the active signal and desktop mode says 165hz, when the 1080p 165hz is the main display it works perfectly fine but i need the 4k 60hz to be my main, thanks in advance.

Answer 1

Hi Kenny,

Making 165Hz your primary fixes this because DWM runs at 165Hz, Discord capture inherits 165Hz timing. Primary monitor controls DWM timing anchor. This is a Windows behavior and not a Discord bug.

You’ve diagnosed this extremely well.

Regards,
Jhun

Answer 2

Hi Kenny,

I think you just found your own fix. If the Discord is the main cause, try disabling the Discord hardware acceleration. After turning it off, restart discord completely.

If that doesn’t fully fix it,

1. Go to User Settings > Voice & Video
2. Turn OFF: “Use our advanced technology to capture your screen” “Use hardware acceleration to encode video” (if visible)
3. Restart Discord.

I hope this will finally fix it.

Regards,
Jhun

Answer 3

Hi Kenny,

With your update, this leaves one specific Windows behavior that matches the symptoms. When the 4K 60Hz display is primary, Windows DWM is frame-pacing the desktop to 60Hz due to hardware plane assignment, not refresh rate output. The GPU is has a 165Hz output, but the desktop compositor is presenting at 60Hz. DWM hardware plane prioritization could be the culprit.

Let's try these new options and let's see if this is the real root cause.

A. Force independent flip on the 165Hz monitor.

1. Open Settings.
2. System > Display > Graphics.
3. Click your 165Hz monitor.
4. Under “Graphics performance preference” set: Add a desktop app (browse to something like explorer.exe) Set it to High Performance.
5. This nudges Windows to prioritize GPU hardware presentation on that panel.
6. Restart after.

B. If A doesn't work, disable "Fullscreen Optimizations" system-wide. This one sometimes works surprisingly often for this exact issue.

1. Go to: C:\Windows\System32.
2. Right-click dwm.exe.
3. Properties > Compatibility.
4. Check: Disable fullscreen optimizations. Run as administrator (optional test).
5. Apply > Restart.
6. This forces DWM to avoid certain flip model behavior.

Regards,
Jhun

Answer 4

Hi Kenny,

So this means that bandwidth limitation is excluded on the problem since you are using a powerful RTX 4070 and uses display ports. More likely we are dealing with a Windows compositor, timing and sync behavior issue and not hardware limits. Let's try these new sets of fixes.

A. Disable G-Sync temporarily.

1. Open, NVIDIA Control Panel
2. Go to Set up G-SYNC
3. Uncheck Enable G-SYNC, G-SYNC Compatible
4. Apply.
5. Then Set 4K as primary and move your mouse on the 165Hz monitor
6. If it suddenly feels smooth > that’s the issue.

B. Force independent flip mode. MPO Fix, common RTX 30/40 series issue. This is a known NVIDIA + Windows compositor bug.

1. Press Win+R
2. Type: regedit
3. Go to: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Dwm
4. Right-click → New → DWORD (32-bit)
5. Name it: OverlayTestMode
6. Set value to: 5
7. Restart PC. This disables Multiplane Overlay and often immediately fixes mismatched refresh presentation.

C. Check hidden NVIDIA setting.

1. In NVIDIA Control Panel, Manage 3D settings > Global Settings.
2. Set: Vertical Sync > Off. Preferred refresh rate > Highest available. Monitor Technology > Fixed Refresh (not G-Sync).
3. Apply > Restart PC.

D. Check your 4K monitor scaling difference. Temporarily set both to 100% scaling. Sign out and back in. Windows sometimes syncs compositor timing across mixed DPI scaling.

Regards,
Jhun

Answer 5

Hi kenny heath,

Good day. I'm Jhun an independent advisor. In regards with your monitor issue, this is a common dual monitor issue in Windows 11 and 10 when mixing 4k at 60Hz and 1080p at 165Hz displays. When 4k 60Hz monitor is setup as primary, your Windows and GPU may sync both display to lower refresh rate due to bandwidth, GPU settings or driver behavior even it shows 165Hz.

Try to do these steps and see what will fix the problem.

A. Confirm true refresh rate.

1. Open: Settings > System > Display > Advanced display.
2. Select the 1080p 165Hz monitor and confirm: Desktop mode = 1920×1080 at 165Hz Active signal mode = 1920×1080 at 165Hz
3. If both say 165Hz but it looks like 60Hz, the issue is likely GPU-level or bandwidth related.

B. Check GPU control panel.

1. If you use NVIDIA, open NVIDIA Control Panel.
2. Go to: Change resolution > Select 1080p monitor > Ensure 165Hz is selected.
3. Then check set up multiple displays. Make sure it’s in “Extend” mode and not clone. Try toggling primary monitor here instead of Windows.
4. Also manage 3D settings > Global Settings Set Preferred refresh rate to Highest available.

C. Check cable and port.

1. Your 1080p 165Hz monitor must be using: DisplayPort (recommended) OR HDMI 2.0/2.1, if monitor supports 165Hz over HDMI
2. Avoid: HDMI 1.4. This often caps at 120Hz or 60Hz depending on setup
3. If your 4K 60Hz monitor is using HDMI, try: 4K monitor on HDMI 1080p 165Hz monitor on DisplayPort
4. Mixing certain ports can cause the GPU to limit timing.

D. GPU bandwidth limitation, specially on older GPUs. Some GPUs, specially older mid-range cards cannot drive:

1. 4K @ 60Hz
2. 1080p @ 165Hz at full bandwidth simultaneously on certain port combinations.

E. Advanced fix.

1. Set 4K monitor to 60Hz.
2. Set 1080p monitor to 165Hz.
3. Make 4K primary.
4. Restart PC.
5. Open GPU control panel and manually re-apply 165Hz again.
6. Sometimes Windows silently re-syncs on boot.

F. For testing disable hardware acceleration in Windows.

1. Go to Settings > System > Display > Graphics > Default graphics settings.
2. Try toggling hardware-accelerated GPU scheduling (off > restart)
3. This has fixed mismatched refresh behavior for some users.

I hope this helps.

Regards,
Jhun