Forcing Triple Buffering?

Lasse B. · Mar 21, 2015

HWiNFO and RivaTuner Statistics Server can be used together to display VRAM consumption in an overlay on top of the game. A frame buffer is "x resolution * y resolution * color depth", so in E

would be 1920*1080*32bpp ~ 63.28MiB. This means that if there is an additional frame buffer, VRAM consumption would be ~ 63.28MiB higher than usual.

With that in mind I took a couple of readings when running E

in the Target Practice training scenario. This is a rather controlled environment as there is no server <> client communication, no NPCs and no players.

Restarting E

and the test scenario with and without changing D3DOverrider's triple buffer setting between sessions has shown that although VRAM consumption is somewhat dynamic, the average VRAM consumption values of both triple buffer enabled and triple buffer disabled are too close to one another to have enough space to fit an additional buffer.

You may have noticed that I'm talking about an "additional buffer" and not a "3rd buffer". The reason for that is that the game might already do triple buffering all by itself. If someone has an idea on how to check for that, please let us / me know.

PS:
I think I should mention that I ran my tests on Win8.1 with no compatibility mode set for E

. I've just read that it would work on Win8.1 if the game in question is ran in Win7 compatibility mode. This would require a new series of tests for which I currently lack the incentive.

sp82 · Mar 21, 2015

Hi Lasse,
I don't think it's possible see an increase in vram usage because of a 3rd buffer. A buffer for an 1920x1080x32bit image it's only 8MB not 64MB, also a rendering buffer it's more than a image buffer, there is also a z-buffer associated to it for sure.
The vram usage depend the scene rendered, the textures loaded and so many other stuff influence the vram usage like antialiasing for example.
My experience with D3doverrider it's based on looking the fps, did you seen changes in the framerate?
you can test it on monitor and on dk2. You can press CTRL+f you show the fps.
if you want the best from the dk2 use it in extended mode and just before start ED disable the monitor (you can use WIN+P to change output).
To see the fps counter in the Oculus you can remove the left lens, and you should see the countr on the bottom corner.

sorry Lasse I didn't read your PS. D3overrider do not work on win8.1 most of the time. Also in win8 you can't disable Aero, so you have one frame on latency in extended mode. I will stick with win7 forever.

Lasse B. · Mar 21, 2015

sp82 said:
Hi Lasse,
I don't think it's possible see an increase in vram usage because of a 3rd buffer. A buffer for an 1920x1080x32bit image it's only 8MB not 64MB, also a rendering buffer it's more than a image buffer, there is also a z-buffer associated to it for sure.
The vram usage depend the scene rendered, the textures loaded and so many other stuff influence the vram usage like antialiasing for example.
My experience with D3doverrider it's based on testing it, did you test it?

F... me, forgot to divide by 8. When I take a screenshot of my desktop it's 1920*1200*24bpp = 6.9MiB. I guess it shows it's been a while since I last had to do with "screen stuff"

As far as testing D3DOverrider is concerned, I get tearing with and without it, no matter what the settings. But, as I said in my previous posting, I didn't yet try it in Win7 compatibility mode.

Caspar · Mar 21, 2015

When you have a game which has a launcher, how do you ensure that the game exe itself launches in Win 7 compatibility mode? If you run the launcher in Win 7 - will everything it calls also launch as Win 7

?

drkaii · Mar 21, 2015

sp82 said:
adaptivesync it's not good for VR because it disable the vsync if your gpu can't render at 75fps. if your avg fps is below 75hz it's like vsync is always off and you get tearing.
triple buffer give you the best of vsync on
( no tearing ) and vsync off ( using all power from your gpu ).

Sorry to single only this thing when replying, I haven't had time to read the whole thread and I won't for a while, but this stood out.

What is wrong with tearing in VR? I think it's much worse in non-VR than in VR. In VR it creates this sort of effect that makes it feel like you are underwater. It's almost actually quite pleasant. Far far better that than nauseating judder...

Lasse B. · Mar 21, 2015

Caspar said:
When you have a game which has a launcher, how do you ensure that the game exe itself launches in Win 7 compatibility mode? If you run the launcher in Win 7 - will everything it calls also launch as Win 7 ?

A child process should inherit compatibility settings from its parent process, but I never gave this much consideration. Any game executable can be found and have it's compatibility set directly, so that's what I went with. Still doesn't matter if triple buffering is enabled in D3DOverrider or not

And three other odd things:
Why do I get tearing for frame rates > my screen's refresh rate, no matter if triple buffer is enabled or disabled?
Why do I get no tearing for frame rates < my screen's refresh rate, no matter if triple buffer is enabled or disabled?
If frame rate < my screen's refresh rate, why does it feel like I'm getting 15fps although the counter shows around 45FPS?
What the cookie baker is going on?

drkaii · Mar 21, 2015

When you computer scientists have figured out what's going on, feel free to leave a non-technical statement about your findings (although following this is turning out to be pretty fascinating!).

Ta.

For now, adaptive sync is amazing for my needs. Thanks again Lasse B

Caspar · Mar 22, 2015

Talking about adaptive sync - AMD have Freesync recently launched - thought this was the right place to put it:
http://www.expertreviews.co.uk/acce...-freesync-launches-with-four-monitors-on-sale

[edit] - Looks like this feature is monitor dependent

drkaii · Mar 22, 2015

Caspar said:
When you have a game which has a launcher, how do you ensure that the game exe itself launches in Win 7 compatibility mode? If you run the launcher in Win 7 - will everything it calls also launch as Win 7 ?

Can't you just set both to launch in win7 mode?

Caspar · Mar 22, 2015

drkaii said:
Can't you just set both to launch in win7 mode?

Yes. It's just a direct property of the exe that is preset. It's been ages since I've had to fart about with PC game tweaking hence a complete lack of familiarity with the basics.

drkaii · Mar 22, 2015

Caspar said:
Yes. It's just a direct property of the exe that is preset. It's been ages since I've had to fart about with PC game tweaking hence a complete lack of familiarity with the basics.

I know what you mean. I calculated the speed of an orbiting planet using the equation for the area of a circle instead of the circumference ... In public. Brought shame on my people. Losing the basics at the cost of the advanced. Not cool

sp82 · Mar 24, 2015

here some technical details about triple buffer and directx:
http://www.reddit.com/r/oculus/comments/2ag0wc/how_to_run_vsync_with_less_latency_repost_for/ciuyamz

seanwasere · Mar 24, 2015

"What is tearing",
tearing sux,
when you move your head left and right It makes the image look like you are looking through glass with water running down it,
and your eyes need to re compensate to the slight momentary distortions in perspective it causes.
It tires the muscles that move your eyes.
When going cross eyed, it hurts a little bit, so you don't do it for very long,
but when you have tearing, your eyes are flipping between crossed eyed, and normal at a very high rate, and only slightly enough to consciously be aware of it,
but the muscles in your eyes are aware of it, and they are getting a workout.
You do this too long, and you will get googly eyed,
and when walking down the street, you meet other googly eyed people, you will feel safe, in the knowledge, that they also, use adaptive vsync when using the oculus rift, just like you do.
View attachment 23891

Kyokushin · Mar 24, 2015

I am using D3D Overrider permanently since a few years. ED is working fine with it. I do not have any stutering, tearing or input lag causet by Tripple buffering.

Of course to enable tripple buffering you need force v-sync ON. You should not use adaptive v-sync, because adaptic v-sync is nothing else than automatically turning v-sync on or off (in case than fps is lower than refresh rate). Dynamic v-sync is worse solution than forcing tripple buffering with forced v-sync ON, because can cause tearing and stuttering in FPS range below sync rate.

drkaii · Mar 24, 2015

seanwasere said:
"What is tearing",
tearing sux,
when you move your head left and right It makes the image look like you are looking through glass with water running down it,
and your eyes need to re compensate to the slight momentary distortions in perspective it causes.
It tires the muscles that move your eyes.
When going cross eyed, it hurts a little bit, so you don't do it for very long,
but when you have tearing, your eyes are flipping between crossed eyed, and normal at a very high rate, and only slightly enough to consciously be aware of it,
but the muscles in your eyes are aware of it, and they are getting a workout.
You do this too long, and you will get googly eyed,
and when walking down the street, you meet other googly eyed people, you will feel safe, in the knowledge, that they also, use adaptive vsync when using the oculus rift, just like you do.
View attachment 23891

Lol!

Good stuff. I think I'll take the "risk"