I must remind everyone that this is a framerate-powered brightness fluctuation. The brightness of specific framerates-changes can be sometimes different. Different GPUs will give different frame rates.teG wrote: ↑28 Mar 2021, 11:49Now that is very stange to me. Even stranger is the fact that cities skylines will show now sign of brightness fluctuation what so ever, which ever settings I throw at it, the only setting that causes the gsync to fluctuate brightness in this game is to set gsync to fullscreen and windowed mode rather than fullscreen mode.
The best way to debug GSYNC brightness fluctuations is to display a framerate indicator, such as from RTSS. Although these are average frame rates (trailing 1 second averages), you can corroborate brightness fluctuations with frametime spikes in the real time RTSS graph.
FSE/FSO/Borderless/windowed will often show different RTSS graph data, which can also help debug all kinds of framerate-powered artifacts. For example, one mode may have a much smaller frametime spike than a different mode (bigger spike = bigger brightness fluctuation), since sync technology & screen mode can influence the size of some frametime spikes, especially for bringing up a menu / dismissing a menu.
The FSE/FSO/Borderless/windowed/GPU/OS/upgrade is simply a cause-and-effect -- as often modifies the framerates/frametimes/spikes -- and thus the root cause of GSYNC/FreeSync brightness fluctuations, especially in imperfect implementations of LFC (Low Framerate Compensation algorithms) of VRR technologies.
It's possible on old PC, your framerates didn't change as dramatically, e.g. framerates only increased a bit. But with new PC, you have more dramatic difference between minimum framerate (throttled by disk, menu, OS, FSO quirks) & maximum frame rate (upgraded GPU). Bigger min-vs-max = bigger brightness fluctuation.
It is important to use the correct debugging tools, and understand that VRR brightness fluctuations is almost always framerate/frametime/spike-powered. Once oneself understands this, it becomes less confusing, and just an annoying display quirk. Though some of this can be mitigated somewhat by tweaking settings. Whatever tool you use (RTSS, MSI Afterburner, whatever), needs to show a framegraph overlay:
Every time, I have ever done this, GSYNC flickering almost always corresponds with graph spikes. And graphs often look different FSO vs FSE vs Borderless. And framerate graphs look different between games. Not all GPUs have the same frame rate. Not all games have the same frame rate. Remember, all GSYNC flickering is framerate powered. Usually a situation where min-max is big (Unchanged minimum framerate + massively increased maximum frame rate).
When you upgrade a PC, some games don't improve framerate behavior smoothly (min-max sometimes becomes bigger.... minimum frame rate unchanged but maximum framerate increases). Other times it is Windows or the CPU that changes the min-max differential (aka bigger framerate swings = more flicker). So, if you understand GSYNC flicker becomes bigger for more spikey framerate graphs.
Perfect VRR should not have brightness fluctuations, but displays are never perfect...
Once this is understood better from the correct scientific perspective, things start to make better sense, even if a bit mildly annoying...
Everything in this thread makes sense to me, because I understand the cause of GSYNC brightness fluctuations. It's a frustrating display limitation that is amplified more on some systems than others.
Also, changing VRR range (easier on FreeSync monitors) can also reduce VRR flickering, e.g. setting min-Hz to 55Hz or 65Hz (as long as max-Hz is at least 2.5x+ min-Hz). But this is harder to do on G-SYNC native chipped displays -- they have more proprietary low frame rate compensation. So it is possible drivers can change the framerate behavior via changes to LFC or settings. Especially if a single NVInspector setting is different between old/new system, too (affecting the framerate spikes differently)...
Now, some settings (GSYNC+VSYNC OFF) changes the appearance of GSYNC flicker versus others (GSYNC+VSYNC ON), because VSYNC ON makes VRR behave slightly differently for frametimes faster than refresh cycles.
Have you ever done framerate graph debugging? If not, then you haven't even started any troubleshooting/debugging GSYNC flicker yet -- go do so now and see what findings you get.