Skyrim Vsync question

[karoza]

Greetings everyone,

I'd like to clarify some things about Vsync in Skyrim. I'm using Realvision ENB Performance version and the settings for Vsync are as such:
EnableVSync=true
VSyncSkipNumFrames=0

This means that Vsync is turned on. But when I'm playing in-game, my FPS can be anywhere from 60-40 and what irks me is that Vsync is supposed to drop my FPS to 45 or 30 (considering Skyrim has triple buffer enabled) if it drops below 60. But this never really happens, I have a smooth transition from 60 to 45 fps and the FPS never really jumps down to 45. So I can be playing at 55 fps and it still feels silky smooth, down to 50 it feels a little worse and all the way at 45 it becomes quite jarring to play because of the sudden FPS drop but it's still very tolerable. If I disable the Vsync in the enblocal.ini, all I get is a little more screen tearing. I'd appreciate it if someone could tell me how exactly the Vsync works here, as I know it's working since enabling it limits my FPS to 60.

I used FRAPS to measure the FPS and the Vsync in Nvidia is turned to use application settings. ipresentinterval in the skyrimpref.ini is also set to 1. I simply cannot understand why my FPS won't suddenly drop to 45 or 30 if the FPS goes below 60 on the FRAPS counter with Vsync enabled.

Thank you very much for taking the time to read this.

[quicksilverva]

Unless I'm not entirely understanding your question, VSYNC or Vertical Synchronization, just caps your frame rate to your monitors refresh rate.

 

IE: If your monitor has a refresh rate of 60Hz, then your frame rate would be capped at 60.

 

By capping frame rate at your monitors refresh rate, it eliminates the screen tearing that you see when your frame rate exceeds the monitors refresh rate.

[karoza]

I've read on multiple sites though, that enabling Vsync will halve your framerate down to 30 or 45 (if the game has triple buffering) if it drops even one frame below 60 FPS. Is Vsync supposed to simply cap my FPS at 60 and remove any screen tear?

[quicksilverva]

VSYNC just caps your frame rate to monitor refresh rate.

 

Triple Buffering as per my understanding, stores an additional frames in memory to feed to the monitor as needed.

 

However, if you use VSYNC, then you should use Triple Buffering, as the they go hand in hand.

[quicksilverva]

Here is a guide on VSYNC, Double Buffering, and Triple Buffering. It can explain it a lot better than I can.

[karoza]

So if I use Vsync from the enblocal.ini and the Triple Buffer from D3DOverrider, will the combo work? Or do I have to use some other Vsync option? Oh, and that article was quite helpful, but I still don't understand why almost every forum says that dropping down to 59 FPS automatically reduces FPS to 30. Is Skyrim using some sort of adaptive Vsync or is Vsync simple not meant to halve my framerate but rather just cap it?

[quicksilverva]

That combo should work.

 

Unfortunately, everything I have been reading about VSYNC, the frame rate droppage is a side effect of VSYNC.

[quicksilverva]

Interrogative: What graphics card are you using, and do you run a constant 60 fps?

 

 

 

Here is a good explanation of the frame rate drop:

 

 

The problem with turning VSync on is that the framerate is locked to multiples of 60. If the framerate drops even just a little below 60 FPS VSync will drop all the way from 60 FPS to 30 FPS. This is a huge drop in framerate, and that large change in framerate becomes noticeable to the gamer. The result is called stuttering, and when you are playing a game that consistently changes between only 30 and 60 FPS, the game speeds up and slows down and you feel this difference and it distracts from the gameplay experience. What's worse is that if the framerate drops ever so slightly below 30 FPS the next step down for VSync is 20 FPS, and then the next step down is 15 FPS.

[karoza]

I'm using a GTX 960M, and no I don't get a constant 60 FPS, it's more like 50-60 FPS 90% of the time unless I remove my 100 or so mods (Flora Overhaul, Realvision, tons of 2K textures, better NPC body meshes and textures, BLESS armor which has a lot of HDT such as moving capes, faulds, epaulettes and belts, lots of script-hungry mods, etc.) which makes the FPS stay at a constant 60. I'm actually quite surprised by how well it holds up considering it's such a low end card.

I just tried out the Triple Buffer and sadly it makes no difference to my FPS. Even if I force the Vsync in the D3DOverrider, the FPS won't go up, and if FRAPS is not supposed to be able to analyze the FPS properly after Triple Buffer, I can confirm that the 40 FPS still feels like 40 FPS before I enabled Triple Buffer to my eyes. I'd rather just stand the occcasional 45 FPS near Falkreath than go meddling with some old software which causes who-knows-what side effects, plus the Vsync is cutting down the screen tear while not locking me to 45 or 30 FPS, so I'm completely cool with it. It's much better than my previous run of Skyrim on the PS3 in 720p at 25-30 FPS and trash visuals xD

Thanks a lot for taking the time to help me out buddy, I guess you can only stress a terribly old game engine so much without expecting pointless FPS drops. I'll just wait for the new 64-bit remastered version which will probably help a little with the stability and might even give a slight performance boost.

EDIT: I can confirm the Vsync is working perfectly reducing the screen tear and capping it at 60 FPS, yet my framerate never jumps from 60 to 30 and then to 20. If someone with a little more insight as to why my FPS isn't 'jumping' can help, I'd be grateful. Just some extra knowledge would be nice to have.

Edited June 29, 2016 by karoza

[quicksilverva]

Eh, no worries mate.

 

One other thing you can try. Disable Triple Buffering, and in the NVIDIA Control Panel, force the card to use Adaptive VSYNC.