Enabling VSync enforces framerate cap

Hi there, the title is a bit silly but hopefully someone can help me out with this.

In the present and previous drivers (388.13, 388.31 and 388.43) I've been experiencing odd behaviour: whenever I enable vsync, be it through the control panel or in-game, the drivers impose a framerate cap of (Refresh Rate) - 2. This even happens when using fastsync. This is not the usual when enabling vsync.

Yes, I've made sure RTSS is not doing the cap nor has the driver such option enabled.
I've tested it with both 60hz and 75hz refresh rates and both get capped at 58fps and 73fps respectively.

Now, I am aware of the whole reduction of input lag when you cap 2 frames below the refresh rate, but I find the frame skipping unbearable and I've been previously using the method posted here by RealNC to great success and wish to continue to do so.

Is anyone else experiencing this? Is this some new feature nvidia implemented in the drivers recently? Maybe some variable that enabled such behaviour?

OS: Windows 7 x64 Pro.

tl;dr:
whenever I enable vsync, be it in-game or through the control panel/inspector, out of nowhere, framerate is capped at 2 frames below refresh rate (58 fps if i use 60hz, 73 fps if i use 75hz). I am NOT using any software to cap the framerate.

Cheers!

edit:
issue resolved, occam's razor: dust in the hdmi contacts in the GPU port and/or not securely plugged in cable, really stupid shite but to great effect.
Hopefully this will save some hours to some poor soul in the internet with a similar problem.

 

Thats what vsync does , it caps your framerate below max refresh to stop tearing , can give you a little mouse lag too

 

No, vsync caps the fps to the monitors refresh rate, not a 2 fps cap below it.

 

Thank you for taking the time to read the thread.

After some more testing, what seems to enforce the cap is the Vertical Sync Tear Control set to Standard/LoL, regardless of vsync method used, tho the 1/2 Half Refresh option plus Standard Tear Control seems unaffected, i.e. doesn't lock to 28fps.

Also tested with two older drivers (385.41 and 387.92) and unfortunately the same behaviour shows up now.

So that leaves me thinking that it might be some recent Windows Update KB... ?
Just speculation until someone else can confirm they experience the same framerate lock.

 

Do not cap 2 frames below, since you're not using a G-Sync or FreeSync panel.

https://www.blurbusters.com/howto-low-lag-vsync-on/

 

Maybe I'm not wording the OP correctly because there are two people confused over the issue now (archie123 and khanmein).

tl;dr:
whenever I enable vsync, be it in-game or through the control panel/inspector, out of nowhere, framerate is capped at 2 frames below refresh rate (58 fps if i use 60hz, 73 fps if i use 75hz).
I am NOT using any software to cap the framerate.

 

Try creating a custom resolution in the nvidia control panel to make sure you're actually running 60 or 75 hz. If that doesn't work try removing the drivers with DDU, and install them again. Also you should post your complete specs, or at least what screen you're using (if your specs on your profile are up to date)

 

No luck with custom resolutions, still locked at 58/73 fps.
BlurBusters Refresh Rate test lists the refresh rates to the expected values, 60hz/75hz.
I always use DDU with every driver install.

Specs on profile are up to date.
Monitor: LG 34UM57.

 

What does vsynctester.com say your actual refresh is?

 

It seems anything hardware accelerated is behaving this way.
vsynctester.com result
nvidia gsync demo

 

The only thing that makes sense to me, is if you had somehow had the frame limiter set globally in Profile inspector.

But if it happens at 75 hz too, that's weird.

 

Yeah, I'm lost on this. I have absolutely nothing capping the framerate, it just so happens when standard vsync is enabled.
What I find even weirder: fastsync behaves the same.
You could argue it's maybe a left over from an old driver, a borked install or the sort, but I've been thorough with scrapping everything from the registry, even going in to manually check and the behaviour still remains.

 

Maybe turn off all the Gsync feature stuff, and turn off Aero.

Does your monitor have multiple inputs? (DVI,HDMI,DP?)

 

Is this happening in Full Screen Exclusive programs, or only in windowed?

 

Tested with GSync stuff forced to off and disallowed: on both occasions, no luck. (This is a freesync monitor, but it was worth a shot).
Aero off: no luck.

Monitor has both DP and HDMI, currently set on DP.
I also have a TV connected through HDMI, but the same thing happens.
Tested on each one independently to see if it was a multi monitor problem, but have ended up with the same result.
VSync should have no bearing on windowed mode since Desktop Window Manager takes over, but nonetheless, if i enable vsync (in-game or in control panel before launching), the cap goes into effect.
So yes, it's happening in both, windowed and full screen exclusive.

 

You could try locating the display in the registry and delete them all.

\HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\nvlddmkm\display database.

Then use CRU To reset the display driver with Restart64.exe. Also use CRU reset-all.exe

 

Did so and nope, same thing.

 

While doing some more troubleshooting, I disconnected the TV and the cap went away.
Then switched over to the TV as main display, ran a test and disconnected the monitor: cap went away.
I have to physically pull the input plug from either device for it to normalize, using Win key+P to only enable each display while the other is connected won't work.
I still have no idea why this suddenly started to happen, this is just odd.

 

Bizarre

 

Well, this was really fucking stupid and laughable, but, in case anyone else comes across something like this:
Unplug the input cables from your GPU, dust them off, plug again.
crap works as it should.

Goddammit.