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Re: G-Sync requiring very low FPS cap?

Posted: 08 May 2017, 09:59
by jorimt
l33tgms wrote: What a bunch of nonsense why even bother to answer to a rhetorical question especially that kind of stupid things
The point was to get a flawless working tech that limit everything out of the box (especially if you pay for it extra or at least without 3rd party software) but you for an unknown reason say that they don't make every game and so on ROFL god you made my day how is that even related :lol: at least you partially understand some of the 1st grade basics haha
I was actually relieved @Sparky answered the question (accurately), so that I didn't have to, but I'll try to answer it in a different way.

G-SYNC adjusts the refresh rate to the framerate. When the framerate exceeds the refresh rate, G-SYNC no longer has anything to adjust and it stops working.

Only fix is to have a really weak system that can't reach your maximum refresh rate (80 fps on 144Hz monitor, for instance), buy a display with a much higher refresh rate (240Hz), or set an fps limit below the refresh rate.

Everything has its limits, I don't know why G-SYNC has to be an exception.

Re: G-Sync requiring very low FPS cap?

Posted: 08 May 2017, 10:16
by l33tgms
jorimt wrote:
l33tgms wrote: What a bunch of nonsense why even bother to answer to a rhetorical question especially that kind of stupid things
The point was to get a flawless working tech that limit everything out of the box (especially if you pay for it extra or at least without 3rd party software) but you for an unknown reason say that they don't make every game and so on ROFL god you made my day how is that even related :lol: at least you partially understand some of the 1st grade basics haha
I was actually relieved @Sparky answered the question (accurately), so that I didn't have to, but I'll try to answer it in a different way.

G-SYNC adjusts the refresh rate to the framerate. When the framerate exceeds the refresh rate, G-SYNC no longer has anything to adjust and it stops working.

Only fix is to have a really weak system that can't reach your maximum refresh rate (80 fps on 144Hz monitor, for instance), buy a display with a much higher refresh rate (240Hz), or set an fps limit below the refresh rate.

Everything has its limits, I don't know why G-SYNC has to be an exception.
I understand that but I was expecting a little bit more for the money! At least they can somehow implement lag-free fps limiter or do something about it or even warn people before they buy. Because this is stupid to limit fps via another software which causes input lag, plus you need to find it (thank god its free), then read about how to do it properly, set it up and so on. I think its in their best interest cuz I'm pretty sure that most of the people who bought g-sync monitors won't think about "proper" setup for the tech they already paid for. It should be a plug-n-play solution

Re: G-Sync requiring very low FPS cap?

Posted: 08 May 2017, 10:26
by jorimt
@l33tgms

If Nvidia were to add a "built-in" fps limiter specifically for G-SYNC, it would have to be at the driver level. AMD does have this for FreeSync, and it adds as much input latency as double buffer v-sync (up to two frames). Anyway, Nvidia does already have a driver-level limiter that can be enabled via a third-party control panel app (Nvidia Inspector), but again, it adds 2 frames delay.

The only low/no latency fps limiters possible are in-game limiters, so the responsibility lies with game developers there.

As for RTSS, it is an excellent alternative for games that don't have their own limiters, with very solid frametime control, and only 1 frame of added delay. To put this into perspective, not all games only add up to 2 frames of input latency with double buffer v-sync, some can add up to 4(!), so if an in-game limiter isn't available, an RTSS limit is far superior to uncapped G-SYNC.

Also, unless you're playing non-demanding games like Overwatch or CS:GO, have a 1080p 60Hz G-SYNC display (144Hz is the norm at this point), or have an extremely powerful system, it's unlikely you're going to reach or exceed your refresh rate in newer games @144Hz (I don't, and I have a i7-4770k & GTX 1080). In these cases, an fps limiter isn't even required.

I've also written an article covering G-SYNC basics/limitations, and will be releasing the third part (relatively) soon, which will cover input latency & optimal G-SYNC settings in detail:
http://www.blurbusters.com/gsync/gsync101/

For now, you can also browse the information in the thread that started my article here:
http://forums.blurbusters.com/viewtopic.php?f=5&t=3073

If you have further questions/concerns, feel free to ask, I'd be happy to answer.

Re: G-Sync requiring very low FPS cap?

Posted: 08 May 2017, 18:40
by sekta
jorimt wrote:
sekta wrote:Lucky you. Try the overclock function and see if you can back me up with my findings.
@sekta you're overthinking all of this, and solely testing by eye with a (likely currently buggy) built-in refresh rate meter is only going to get you so far.

I've been doing actual input latency tests with actual measurement equipment for two weeks now (WITH the Creators Update), and I can assure you, that at 144/165Hz with G-SYNC + v-sync on (Nvidia Control Panel) + fullscreen mode + in-game FPS limit of 3 below your current refresh, single, complete, tear-free frames are being displayed to your monitor as fast as the scanout rate (and your system) will allow.

Also, avoid "Adaptive G-SYNC" (G-SYNC + v-sync off), as it will tear at any point it think it can't adhere to the current scanout period, which will happen at any point there is a sudden frametime difference between one frame and the next.

Any other behaviors you are experiencing are down to your system and/or specific configuration issues.
I may be being overly cautious about hitting the refresh rate limit, as the spikes are so fast that it won't affect input lag. However, overclocking past 150 Hz on my monitor does have a negative effect on the image. I can strafe side to side and every 5 seconds or so there is a stutter. The refresh rate overlay isn't bugged in this case, it hits the limit each time it stutters. That stutter is what led me to test all of this. At 165 Hz, I don't care if 157 fps avoids the input latency on average if it is going to be stuttering. What to take away from this is that the overclock function needs to be tested on a per user basis because thats where problems can occur, and a lower limit is needed to avoid hitting the refresh limit even for split second occurrences.

Re: G-Sync requiring very low FPS cap?

Posted: 08 May 2017, 18:57
by jorimt
@sekta, your specs, monitor model?

Re: G-Sync requiring very low FPS cap?

Posted: 08 May 2017, 19:02
by sekta
jorimt wrote:@sekta, your specs, monitor model?
Ill copy paste off my steam profile

MONITOR: Acer Predator XB271HU
MOBO: GIGABYTE G1 Sniper 5
CPU: Intel® Core™ i7-4770K Processor
RAM: G.SKILL TridentX F3-2133C9Q-32GTX
GPU: NVIDIA GeForce GTX 1080 Founders Edition
SSD: Corsair Force Series™ GT 120GB
SSD: Samsung 850 EVO MZ-75E500BW 500GB
SSHD: Seagate Firecuda ST2000DX002 2TB
WLAN: ASUS PCE-AC88 AC3100 Dual-Band PCIe Wi-Fi Adapter
PSU: Seasonic Platinum-1000

Games are on the Samsung 850 EVO.

I am of the unlucky few that have this bug on the monitor, so 144 Hz is not usable for me: http://community.acer.com/t5/Predator-M ... d-p/418751

Re: G-Sync requiring very low FPS cap?

Posted: 08 May 2017, 20:13
by jorimt
We have similar specs (see my sig in this forum). I have the identical monitor, and the identical bug, but it doesn't bother me much, and I use 144Hz as my main refresh rate without issue. The bug crops up very rarely (triggers sometimes when changing refresh rates/resolutions), and when it does I simply go to my menu and toggle the aspect mode back and forth. It's likely the scaler, and it happens regardless of input (HDMI/DisplayPort) or G-SYNC on/off.

I can't say I've experienced the stutter you're describing at 165Hz. I'll give it a try again, see if I can replicate, and report back later.

Re: G-Sync requiring very low FPS cap?

Posted: 08 May 2017, 21:16
by jorimt
Yeah, no, I'm not experiencing the stutter.

Overclocked to 165Hz, G-SYNC + v-sync on (Nvidia Control panel) + 162 fps in-game limit, loaded up an offline no-bot deathmatch, and perfectly smooth.

If you have the Creators update, it did add a couple of new options, including game mode and fullscreen optimizations. I have neither enabled, so they could (or could not) be a contributor; I haven't had the time to test them in-depth yet.

Re: G-Sync requiring very low FPS cap?

Posted: 08 May 2017, 22:15
by sekta
The stutter was happening on the "Aim Botz - Training" workshop map whilst strafing back and forward.

https://youtu.be/RNaJSigkNK0

You can see it happen at 1 second, 12 second, 24 second, 36 second. Obviously a pattern there.

Game Bar is disabled. Game mode in the game bar is disabled. Game mode in Settings is on. Fullscreen optimisations, i haven't touched. Pretty much default except I disabled Game Bar.

Re: G-Sync requiring very low FPS cap?

Posted: 09 May 2017, 00:01
by jorimt
Those just look like plain old frametime spikes to me (e.g. not G-SYNC related), especially with the framerate dropping for a split second, and then recovering shortly after. Are you sure it isn't that particular map causing the issue due to some sort of repeated background asset load?

Also, have you tried performing this test with G-SYNC disabled to see if it changes anything? Because G-SYNC itself really can't cause stutter; only the system/game engine can.