question about Vsync

[Samor]

ok, this could be as much hw-related as sw-related, but I needed to pick one of these forums....
On my new PC, there's several older or low-spec games I run, and naturally they run very fast with vsync off, with framerates around or above 200FPS not being uncommon.
However, of course, with vsync off you notice tearing, which is not nice, so I turn vsync on, which makes the games run at 60fps (the monitor's running in 60hz).
This makes games appear visually very smooth, but with some games I notice the occasional stutter, whereas other games run smooth all the time.
What I want to know is why this happens, why it doesn't happen in some games but does in others, and if there's any way to influence this behaviour.
I don't consider it a big problem, but I'd like to know more about it....

[RPGW1ZaRD]

Is that in newer games it suddenly stutters? If so I'm pretty sure it just drops below 60 FPS and since Vsync makes it drop to 30 FPS even if it's only 1 FPS below 60 when your monitor is running at 60Hz. If you have to use Vsync, then see to it that triple buffering is activated in graphics card settings (disabled by default) as it helps a lot with Vsync enabled.

I personally don't like Vsync at all and that's why I'm still using this highend CRT to run at 100Hz and Vsync is always turned off as CRTs handle high FPS without getting tearing waaaayyy better. Even in old games with 200 FPS+ I don't notice tearing with this monitor.

This article covers this topic up a bit Triple buffering: improve your PC gaming performance for free | GameCritics.com

[refraction]

you running a dual core AMD by chance?

[Cid Highwind]

Samor has a C2D

From what I know about Vsync is that it makes the videocard wait for an entire frame to be rendered before it will be displayed. If your videocard for whatever reason cannot get that one frame rendered in time it will causethat stuttering you notice. Buffering will help, but it will cause some sort of lag. You will always be a few frames behind, and the LCD has some lag itself as well. I doubt you'll really notice it, unless you're incredibly picky and want to join FPS tournaments.

V sync is a hit and midd solution, I avoid it and just use triple buffering instead.

[Samor]

Fraps displays a constant 60 fps at all times while it happens. They're older games, so no, it's not the games running too heavy.

Cid, how can you use just triple buffering and no vsync? IIRC the nvidia driver (at least, in my case) uses Triple buffering when you have vsync enabled, but not without. Anyway, I've had triple buffering on and off (in nvidia's driver settings), and it does not appear to make a difference....

With vsync disabled, I noticed the tearing to not be constant. it's sometimes heavier. This would correspond with where it stutters with vsync on. - odd? As for the framerates, without vsync they're running around 200fps. Shouldn't be the problem...

[Cid Highwind]

It requires some registry tweaks, try a google for Coolbits, that should allow you to use some more options. I also advise using the retro menu rather than that new interface.

[Nucking Futs]

Originally Posted by Samor

Fraps displays a constant 60 fps at all times while it happens. They're older games, so no, it's not the games running too heavy.

Cid, how can you use just triple buffering and no vsync? IIRC the nvidia driver (at least, in my case) uses Triple buffering when you have vsync enabled, but not without. Anyway, I've had triple buffering on and off (in nvidia's driver settings), and it does not appear to make a difference....

With vsync disabled, I noticed the tearing to not be constant. it's sometimes heavier. This would correspond with where it stutters with vsync on. - odd? As for the framerates, without vsync they're running around 200fps. Shouldn't be the problem...

What's the reaction time of your monitor?

[RPGW1ZaRD]

To eliminate stuttering issues is kinda difficult, could depend on so many things. It may be a software running in background (mind only such thing as a newer version/update of a software may be more CPU hogging too). It could be a bad driver or a setting, BIOS option and sometimes hardware combination has to be taken into account. It may be faulty hardware or PSU that is too weak or could be because of overheating (especially mem chips on gfx card). The HDD perhaps is about to fail or contains lots of bad sectors (it's good to do a "chkdsk x: " cmd run every now and then to be sure) or it could be the monitor/HDD/GFX card etc power cable is lose or of course the game itself is badly coded.

I once noticed I had gotten stuttering even in the old fav games such as UT GOTY that always ran uber smooth without a single stutter and it turned out an updated version of a software I usually run in the background had gotten some excessive CPU usage bug in it.

But does those games that stutter run fine without vsync enabled then if we exclude the tearing?

[Allnatural]

Originally Posted by RPGW1ZaRD

If you have to use Vsync, then see to it that triple buffering is activated in graphics card settings (disabled by default) as it helps a lot with Vsync enabled.

That only effects OpenGL apps. If you want to use triple buffering in Direct3d you'll need a third-party program (like D3DOverrider).

[Samor]

Originally Posted by RPGW1ZaRD

To eliminate stuttering issues is kinda difficult, could depend on so many things. It may be a software running in background (mind only such thing as a newer version/update of a software may be more CPU hogging too). It could be a bad driver or a setting, BIOS option and sometimes hardware combination has to be taken into account. It may be faulty hardware or PSU that is too weak or could be because of overheating (especially mem chips on gfx card). The HDD perhaps is about to fail or contains lots of bad sectors (it's good to do a "chkdsk x: " cmd run every now and then to be sure) or it could be the monitor/HDD/GFX card etc power cable is lose or of course the game itself is badly coded.

I once noticed I had gotten stuttering even in the old fav games such as UT GOTY that always ran uber smooth without a single stutter and it turned out an updated version of a software I usually run in the background had gotten some excessive CPU usage bug in it.

But does those games that stutter run fine without vsync enabled then if we exclude the tearing?

yes.
I guess my initial post is too vague. I'll try to be more clear, but it's hard (since it's a vague thing), and certain things might be too easily adressed to a specific game when I doubt it's the case
...and I AM running Vista (32-bit) and have a Geforce 8800GTX, so one could easily adress issues to the beta-state of the drivers,
however, I don't want to say it's probably that and be done with it so easily (also, it's not like I tried just one driver either - basically a new one every week). It could be, but it could be something else as well. That's why I'm asking - if anyone is onto what this is then I'd like to know, wether it's solvable or not. I just don't really like being in the dark about this, small issue or not.

low-spec games I tried were Sonic Heroes (runs smooth without any stutter), LFS (same), Gurumin (occasional stutter) and Virtua Tennis 3 (occasional stutter).
All the games show constant 60fps in framerates with vsync on, and much higher with vsync off (Virtua Tennis 3 runs at around 180fps then, Gurumin goes up to 400).
Gurumin stutters more in Map screens, and that's where Tearing is also much more noticeable with vsync off, yet, the framerate is fine at all times. In virtua tennis 3, with vsync off, tearing occasionally increases in the same manner as the game would stutter with vsync on.

TDU is a heavier running game, it has stuttering but this is a known issue with the 8800GTX and seems to be a different kind of stutter (it always does at the exact same spots, for one, and it seems to be performance-related) - however, at the parts where that game isn't stuttering it runs smooth, despite being BELOW 60fps in certain areas. Oddly enough the syncing goes slightly weird (not stuttering, but a sort of half-tearing) when alt-tabbing out and back to the game, which might be a related thing.

I also tried the colin mcrae dirt demo, which also didn't reach 60fps (but around 40-50), and it ran smooth.
This makes me believe that the stuttering games MIGHT actually run smoother if they DIDN'T reach 60fps. ... and here I was thinking 60/60 would be ideal. Apparantly that only goes for consoles....

There also was an issue with Kega Fusion (emulator) where it would sometimes have a stutter in desktop mode, and sometimes it wouldn't, but never in fullscreen mode, despite running in 1680x1050 60hz in all cases (yes, also in fullscreen mode).

The tearing is more annoying than the vsync stutter, so vsync wins for now =P
...and I guess I'll have to see what rivatuner can do.


Nucking, you mean the response time?

[Nucking Futs]

Yeah, that's what i wanted to know.
I was also wondering when yout started experiencing this problem.

[Samor]

Ever since I have this PC. I just didn't really take notice at first.

First noticed it in Gurumin, but then I thought ...hm.. whatever, prolly something with this game.

Then there was that strange issue with Kega Fusion and when Virtua Tennis 3 then had the same issue as Gurumin I started to wonder about it.


Response time is 16 milliseconds.
(Dell 2007WFP)

[Nucking Futs]

So you bought this whole rig in one piece i guess.
You could try using another monitor to distinguish if it's due to the (rather) slow response time, but i guess it's not.
Other than that i guess it's more of a drivers issue.

[Samor]

I can confirm now that it only happens in Vista.

Is that a crappy OS or what?

[RPGW1ZaRD]

Originally Posted by Samor

I can confirm now that it only happens in Vista.

Is that a crappy OS or what?

Well what I discovered it's certainly not a "gaming" OS as of yet.

[Samor]

indeed, not nearly.
I wonder who's to blame more... nvidia or ms. Definately dissapointing. Even if the OS is young, I think it's quite ridiculous.