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LG 27gx790a-b + GMKtec K8 Mini PC 8845HS 480Hz problem

Posted: 30 Oct 2025, 10:36
by spinek2
Hi, I have a problem. I am buying this configuration in order to achieve 480Hz for CRT beam simulation. The computer has a DP2.1 connection and I connect it to the monitor with a good cable.
Unfortunately, I can only get a maximum of 240Hz under Windows 11 and in Batocera, where I run CRT beam simulations.

Does anyone have a similar configuration? How can I get 480Hz? I tested the monitor's native resolution of 1440p, but also 1080p. The computer manufacturer is not interested in helping. I am still waiting for support from LG's technical department.

Re: LG 27gx790a-b + GMKtec K8 Mini PC 8845HS 480Hz problem

Posted: 30 Oct 2025, 18:03
by Chief Blur Buster
spinek2 wrote:
30 Oct 2025, 10:36
Hi, I have a problem. I am buying this configuration in order to achieve 480Hz for CRT beam simulation. The computer has a DP2.1 connection and I connect it to the monitor with a good cable.
Unfortunately, I can only get a maximum of 240Hz under Windows 11 and in Batocera, where I run CRT beam simulations.

Does anyone have a similar configuration? How can I get 480Hz? I tested the monitor's native resolution of 1440p, but also 1080p. The computer manufacturer is not interested in helping. I am still waiting for support from LG's technical department.
1. Do you have additional displays? Disconnect them and make the 480Hz primary.
2. Try the other ports on the GPU (test all the DisplayPorts on the card)
3. Try the other ports on the monitor (test all the DisplayPorts on the monitor)
4. Enable DSC and/or disable HDR. If you've force-disabled DSC you may not be able to access 480Hz
5. I've seen cables included with monitors have problems -- e.g. a DP 2.1 cable that is defective enough to behave at a slower DisplayPort cable. Try another cable "anyway"; those 77 Gbps cables can sometimes halve bitrate if a wire/connector is flaky. This simply manifests itself as unable to access higher Hz.

Meanwhile, you can preview the new TestUFO 3.0 CRT simulator at https://beta.testufo.com/crt

Re: LG 27gx790a-b + GMKtec K8 Mini PC 8845HS 480Hz problem

Posted: 14 Nov 2025, 10:02
by Zirek
I used the new modeler to counteract the light from the CRT beam.