VSYNC OFF (Use 3D application setting, off ingame)
162 FPS RTSS = shudder/hitching, refresh rate at steady 162 with constant split second spikes down to 130/140 up to 164/165
162 FPS Ingame = shudder/hitching, refresh rate fluctuating wildly and hitting limit
162 FPS RTSS & Ingame = Extreme microstutter
VSYNC ON (Forced On in Nvidia Control Panel)
162 FPS RTSS = smooth but very consistent hitching, steady 162 with constant split second spikes down to 130/140 up to 164/165
162 FPS Ingame = smooth but very consistent hitching, refresh rate wildly fluctuating and hitting limit
162 FPS RTSS & Ingame = Same as just 162 ingame
Whenever it hit the limit, it wasn't always 165, it was mostly staying at 164. If left uncapped, the refresh rate would be mostly 164 with flickering to 165. So for input lag reduction, I think it would be best to have the spikes hit a maximum of 3 below the refresh rate.
The ingame limiter looks pretty bad compared to RTSS so I stopped using it and used RTSS only and dialed down the limit until the hitching stopped. At 165 Hz it became noticeable smoother once I hit <150 FPS, however there is still the constant split second refresh rate spikes down to the 130 region up to the 150 region every few seconds but it's no longer hitting the refresh rate limit and the hitching is much less noticeable.
I'm wasn't sure if this was because of the 165 Hz overclock on the monitor, since it is native 144 Hz and the GSYNC module may only work correctly to 144 Hz so I reduced the overclock. 160 Hz and 155 Hz both suffered from the split second refresh rate spikes. However 150 Hz worked perfect. No spiking at all. This was a relief because my monitor has the faulty firmware where at 144 Hz a strip of pixels in the center gets cut out and moved to the right side. I'm not sure if this is specifically my monitor that can't handle the overclock or if it is the GSYNC module.
So at 150 Hz, the fluctuation completely stopped. No shudder or hitching. At 147 FPS (RTSS) it remained stable with the refresh rate being 146/147/148. That is still too close to the limit for my tastes. With VSYNC OFF, the screen had noticeable tearing/artifacting at the very bottom while strafing back and forward past solid black and green. At 138 FPS this pretty much went away and I couldn't make it tear.
Using the ingame limiter too close to the RTSS limiter with VSYNC disabled made it microstutter pretty badly. I was thinking of having the CSGO limiter act as a low latency limiter and RTSS controls any upward spikes but it doesn't work when VSYNC is disabled. With VSYNC On, the microstutter is gone but the refresh rate fluctuates wildly still. Having VSYNC off revealed how bad it is to have the ingame limiter and RTSS limiter active at the same time. Does VSYNC fix it or just hide it? Not sure so I don't recommend doing it. Set the ingame limiter to the refresh rate maybe and leave it there. I know some games have bad input lag if you completely disable the ingame limiter.
Setting RTSS to cap at 146.5 FPS was better than 147 FPS limit. The refresh rate limit flickered constantly at 146/147 instead of 146/147/148. Reaching 2 FPS below the limit is cutting it close. 3.5 FPS cap below the refresh rate seemed good. Maybe a little lower if the ingame limiter interferes with it with VSYNC off. I disabled VSYNC to test the interference, with 146.5 RTSS limit, ingame fps_max 146 had extreme microstutter and went away at 148. I ended up just setting the ingame limiter to the refresh rate, 150 and saw no downsides. It's probably better to do this than to downright disable it as that can lead to problems with some games. Strafing and spinning rapidly the FPS/Hz did not budge from 145.
After reenabling VSYNC and opening the game again, I was once again getting the weird split second refresh rate spikes downward to 130 region every few seconds. I was also able to spin around and hit 150 Hz. Not sure if this is because of the Creators Update or if it is the gimmicky overclock function on these monitors. The game looked smooth though...without the overlay I wouldn't notice. Still really annoying how everything was working perfectly and then a restart ruins everything. Rebooted, tried VSYNC forced off and VSYNC forced on and was able to hit 150 Hz while spinning. When set to Use 3D application setting, I couldn't hit 150 Hz. Reenabled VSYNC and once again, couldn't hit 150 Hz and it was stable. VSYNC on I can't tell any difference in input lag and it hides any microstutter from RTSS/Ingame limiter collision and bottom screen tearing but at the same time it is a hit or miss whether the refresh rate is stable or not. Every time I set VSYNC to "Use 3D application settings" it is smooth and consistent. To finish up the settings to see if I could tweak it and make it any more consistent, I tried the FPS limit trick used for removing double buffer VSYNC lag, setting a limit of 0.007 below the refresh rate. So I tried 0.007 below my target VRR of 144, 143.993. The refresh rate overlay was just a constant 144 instead of flicking between 143 and 144, or 143/144/145 when set to 144 FPS.
In the end, I settled upon 150 Hz refresh rate, 143.993 FPS limit in RTSS, 150 FPS limit ingame (this didn't matter), VSYNC "Use 3D application settings". Results in a very smooth 144 Hz experience.
Anyway final points...
- If your monitor overclocks, reduce the overclock until the the refresh rate stops spiking.
- Use Rivatuner Statistics Server to limit the FPS.
- Enable VSYNC in the control panel or "Use 3D application settings".
- Don't use both ingame limiter and RTSS at the same value at the same time. Disable VSYNC and adjust the ingame limiter until microstuttering stops, this is when the ingame limiter doesn't negatively affect the RTSS limiter. Reenable VSYNC if you had it on.
- Limit at least 3.5 FPS below refresh rate. Lower could be better, would need benchmarking.