Custom Resolution Utility (CRU)

[aelius]

(09-02-2022 02:12 AM)Dreamic Wrote:  I don't think it's a fault of your program but something dumb Nvidia is doing and I think should be added to the Editing VRR Range section, not sure if there's been discussion about this.

In order to lower my VRR/LFC Range from 80 to 30, changing it is not enough. I must also change the Device ID to something with a lower VRR Range, like DELA179 (Dell/Alienware AW2721D 1-240Hz). Mine is SAM105C (Samsung Odyssey G7 80-240Hz).
This is the only way to go below 80Hz VRR. Reset Device ID to SAM105C and it will no longer go down to 30Hz~.
Also the Nvidia database is wrong about this display being 60-240Hz, it's 80-240Hz.
Everything is as up to date as it could be, monitor firmware included.

I don't think everyone will figure this out, why their 40fps in GSync Pendulum is 80Hz instead of 40Hz or 70fps is 140Hz, it's because of Device ID, LFC doubling isn't changed unless Device ID is to a correct one.
And we know LFC on certain displays, I think I've heard mainly VA, results in a brightness shift/flicker, as Hz jumps from 75Hz to 150Hz etc when you drop to 75fps, 85fps will be back at 85Hz. This is how you fix/mitigate this.

Increasing the variable refresh range to dip down into 30Hz is a really bad idea, because the pixel response time and input lag will skyrocket, and if you ever dip below 30Hz the flicker will be way WORSE than before. There's a reason stock LFC kicks on as high as 80Hz.

A better approach is to shrink the variable refresh range. Flicker becomes harder to notice in the higher Hz, so you can leverage your 240Hz of headroom to make the range 120Hz-240Hz. Be sure to make it exactly 1/2 of the actual max Hz (239.something). You can go even smaller, if you like, but you'll create a gap in the coverage. A range of 150Hz-240Hz won't be able to engage variable refresh from 121fps-150fps, for example.

fwiw, flicker should only ever occur if you've got poor frame pacing, so the easiest fix is always to investigate why the game is running poorly. Many games are just unfixable though