Gsync ON or OFF when FPS always matches refresh rate?

Talk about NVIDIA G-SYNC, a variable refresh rate (VRR) technology. G-SYNC eliminates stutters, tearing, and reduces input lag. List of G-SYNC Monitors.
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r3lik
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Gsync ON or OFF when FPS always matches refresh rate?

Post by r3lik » 31 Jul 2020, 01:13

Hello all,

Long time lurker, finally signed up.

As the question states in the subject, should Gsync be ON or OFF when FPS==monitor refresh rate? To my understanding, there is no benefit to having Gsync on in that scenario, and it could be better to use ULMB in that case.
Is there an input lag penalty for having Gsync enabled when there is no need for it in terms of variable refresh rate?

Thanks!

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Chief Blur Buster
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Re: Gsync ON or OFF when FPS always matches refresh rate?

Post by Chief Blur Buster » 31 Jul 2020, 01:26

r3lik wrote:
31 Jul 2020, 01:13
Hello all,

Long time lurker, finally signed up.

As the question states in the subject, should Gsync be ON or OFF when FPS==monitor refresh rate? To my understanding, there is no benefit to having Gsync on in that scenario, and it could be better to use ULMB in that case.
Is there an input lag penalty for having Gsync enabled when there is no need for it in terms of variable refresh rate?

Thanks!
Yes & No -- depends on your goals.

If you're trying to avoid VSYNC OFF, then framerate-capped G-SYNC has lower input lag than ordinary VSYNC ON. For example, if you have a 165Hz monitor, use an approx 162fps cap to have very easy low-latency VSYNC that's not fiddly, and will be forgiving during frame rate dips.

However, if you're playing competitively, then framerates massively beyond refreshrate, during VSYNC OFF, can produce lower latency, due to the way ultra-high VSYNC OFF framerates literally streams multiple frameslices per refresh cycle in real time during scanout. Screens refresh from top to bottom (www.blurbusters.com/scanout) and VSYNC OFF can essentially splice new frames mid-scanout, without waiting for the next refresh cycle to begin. However, there are side effects such as tearing and/or microstutters. For this reason, CS:GO gamers often play using VSYNC OFF. However, with upcoming 360Hz monitors, the opportunity arises to have a framerate range completely within VRR range, in a larger selection of games, and the ultra-fast 1/360sec scanout, makes VSYNC OFF less necessary.
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       • Official List of Best Gaming Monitors
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r3lik
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Joined: 31 Jul 2020, 01:08

Re: Gsync ON or OFF when FPS always matches refresh rate?

Post by r3lik » 31 Jul 2020, 01:53

Thanks, I will continue to keep using GSYNC ON, VSYNC ON + Frame-rate cap.
Love the site!

r3lik
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Re: Gsync ON or OFF when FPS always matches refresh rate?

Post by r3lik » 31 Jul 2020, 13:47

If you constantly push 139 fps and cap frames does it still make sense to use gsync on, vsync on in that scenario. There is no VRR here, right since you're always at 139 fps?

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jorimt
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Re: Gsync ON or OFF when FPS always matches refresh rate?

Post by jorimt » 31 Jul 2020, 14:05

r3lik wrote:
31 Jul 2020, 13:47
If you constantly push 139 fps and cap frames does it still make sense to use gsync on, vsync on in that scenario. There is no VRR here, right since you're always at 139 fps?
VRR is still fully active at 139 FPS 144+ Hz.

You don't need a constantly fluctuating framerate to benefit from VRR, as it's still matching the display rate to the render rate so long as the FPS is within the refresh rate, which equals no sync-induced input lag or sync-induced stutter, and no tearing.

There's really no situation where it's better to use standalone V-SYNC if fully featured VRR is available to you. The only real exception is if you're strobing and need tear-free FPS = Hz, at which point you can't use VRR anyway (unless you have a ELMB-Sync-capable display).
(jorimt: /jor-uhm-tee/)
Author: Blur Busters "G-SYNC 101" Series

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r3lik
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Re: Gsync ON or OFF when FPS always matches refresh rate?

Post by r3lik » 31 Jul 2020, 14:07

Thanks, that makes more sense.

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