Will G-sync ever be fluid at capped 30 fps?

[fenderjaguar]

I've noticed that G-sync is fluid at between 31/32 fps, but if you cap any lower, it starts stuttering a little. Really what is the issue with this, since the monitors can run at 30hz (not to mention down to 24hz).

If you ever used quarter refresh vsync on 120hz or half refresh vsync on 60hz, you know that 30 fps fluidity that you get for certain console games, ie. halo combat evolved or sonic all star racing. Yes they are few and far between, but some games are meant to be run at 30 fps, or will ONLY run at 30 fps, and we shouldn't have to be suffering this horrible 60hz half refresh vsync input lag, just to get a smooth frame rate, when we have very low input lag g-sync, even at 30 fps.

[fenderjaguar]

So nobody has noticed this? Try capping a game at 30 fps with rivatuner statistics server in gsync mode with a decent variable frame rate engine. Watch it stutter at 30 fps, but it's fine at 32 fps.

[PoWn3d_0704]

Yeah, anything below 45fps and my whole screen starts to flicker.

I don't care that much, since 60-144 looks so good.

[fenderjaguar]

Yeah, anything below 45fps and my whole screen starts to flicker.

I don't care that much, since 60-144 looks so good.

Yeah, I know what you mean about that flickering. Though it isn't really noticeable, it's more like a speccly tingling sensation on the screen. And that's not what I'm talking about, btw, I'm talking about the fluidity of the frame rate.

[flood]

as an alternative you can try 120hz + vsync; i think the additional lag from vsync would be negligible for 30fps games

[Sparky]

The monitor can't refresh the panel slower than 30hz without flickering, so when the framerate drops that low, it repeats the previous frame. Repeating the previous frame takes about 7ms, so the frame time jumps from 33.3ms to 40.3ms. This means you get judder between 24.8 and 30fps.

There are ways around that if the max refresh rate is more than double the minimum refresh rate, but as far as I know, neither AMD nor Nvidia has implemented window shifting yet. Basically, if you think the frame will take longer than 33ms, you put a forced refresh around 20ms, so that if the frame finishes anywhere between 27 and 60ms, you don't get any extra stuttering.

[BlackGuyRX]

Can it be fixed with a software update or will it take a whole hardware revision?

[fenderjaguar]

as an alternative you can try 120hz + vsync; i think the additional lag from vsync would be negligible for 30fps games

That makes the frame rate stutter as well, sometimes. You'll have a period of about 60 seconds where the frame rate is perfectly smooth, then microstutter city for a short period, then back to being completely smooth. I think it happens when the tear reaches the bottom of the screen, were vsync not enabled (ie, the buffer runs out, if you know what I mean)

You have to use 120hz and quarter refresh vsync for it to be right. I understand what you're saying about input lag, but that is not my point, only the fluidity of the frame rate

http://i.imgur.com/E9EQNTC.jpg

Same with 60 fps capped on 120hz with normal vsync. You'd have to use half refresh vsync for it to be perfectly smooth all the time.

[fenderjaguar]

The monitor can't refresh the panel slower than 30hz without flickering, so when the framerate drops that low, it repeats the previous frame. Repeating the previous frame takes about 7ms, so the frame time jumps from 33.3ms to 40.3ms. This means you get judder between 24.8 and 30fps.

There are ways around that if the max refresh rate is more than double the minimum refresh rate, but as far as I know, neither AMD nor Nvidia has implemented window shifting yet. Basically, if you think the frame will take longer than 33ms, you put a forced refresh around 20ms, so that if the frame finishes anywhere between 27 and 60ms, you don't get any extra stuttering.

These monitors could be made to refresh at 24hz, before the gsync kit was fitted though. Yeah, you get that speccly tingling slight flickering, but I really think they should have had something slightly lower than 30hz as the minimum refresh.

Also the frame rate isn't going lower than 30 fps, it's capped fixed holding at 30 fps precisely. the monitor still 'flickers' at 30hz (hell, like PoWn3d_0704 says, it even flickers at 45 fps if you're really looking for it), so it's not like a minimum refresh of 29hz or 29.9hz would be any more noticeable, but it would mean 30 fps would not stutter.

[fenderjaguar]

Can it be fixed with a software update or will it take a whole hardware revision?

Maybe it's something inherent to the actual g-sync hardware kit and they won't be able to make the minimum refresh any lower than 30hz, even with drivers etc.

I really think nvidia should take a look at this, because if you want to play 30 fps capped with gsync, it currently isn't good. I would have started talking about this when I first got the monitor nearly a year ago, but I really thought they'd have sorted this out now. I think it's slipped under the radar because of 30 fps being regarded as inferior, but it is what it is.