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x64 old renderer appears sluggish

Posted: Sat Nov 19, 2016 2:17
by Nash
First up, good job on the new triangle renderer! It runs at a much more acceptable and playable framerate now and doesn't flicker like mad. Excited to see it progressing further!

Anyway on to the bug report. With the old, TC Doom renderer, the video appears to be stutter and slugging. vid_fps shows 60, regardless if vid_vsync is turned on or off. Moreover, my vid_maxfps is set to 0 so I shouldn't be getting any caps.

It looks and feels more of like 40 - 50 FPS, despite the frame rate counter saying it's 60.

Re: x64 old renderer appears sluggish

Posted: Sat Nov 19, 2016 3:16
by dpJudas
Hmm, the old renderer in TC mode usually runs at 180-200 FPS here at 1920x1080 (at least on vanilla maps) - way beyond the range you list. Is mulithreaded rendering enabled on your computer?

I have noticed that if the frame rate drops below something in the 130+ range on my computer then it no longer feels smooth. Why that is I've never fully understood as I play GZDoom vsync locked at 60 fps without that. But I'm pretty sure it has something to do with ZDoom and not directly a QZDoom thing - i.e. ZDoom does the same thing if you manage to get the frame rate low enough. I'd love to know what is causing it.

Re: x64 old renderer appears sluggish

Posted: Sat Nov 19, 2016 3:36
by Rachael
Try swapping between the OpenGL and Direct3D framebuffers as well. Some cards - especially older cards but it seems to be the case with newer ones too - seem to be more responsive on the Direct3D framebuffer than the OpenGL one. This could be a Microsoft thing, though...

Also if you are on the D3D framebuffer, make sure to swap D3d_Antilag on or off. I have no idea why this was implemented but it doesn't do what it says it does...

So between mine and dpJudas's posts, here are the CVars you should try swapping around to see what effects they produce:

Code: Select all

vid_used3d
r_multithreaded
d3d_antilag

Re: x64 old renderer appears sluggish

Posted: Sat Nov 19, 2016 7:27
by Nash
Found the problem! "Software canvas" was unknowingly set to "OpenGL" in the renderer menu. I set it back to Direct3D, relaunched QZ and everything is butter smooth now. =D

I guess this is [Not A Bug]? :S But at the same time, you might want to investigate why the OpenGL canvas is sluggish...

Re: x64 old renderer appears sluggish

Posted: Sat Nov 19, 2016 8:45
by Rachael
Indeed, but I am not sure if it is a problem that can be solved on QZDoom's side. There may just be some operation that's making it slow, or there may be an actual issue. Out of curiosity, what graphics card do you have?

Re: x64 old renderer appears sluggish

Posted: Sat Nov 19, 2016 12:40
by dpJudas
Seems vsync wasn't working properly in the GL target on my Nvidia card. I pushed a fix for that.

The performance of the OpenGL target seems to be depend a lot on exactly what it does to a buffer allocated with the GL_DYNAMIC_DRAW flag. On my computer, it makes it faster than the Direct3D version, but seems for other people it has the opposite effect.

Interestingly, enabling vsync makes the rendering seem as smooth as with GZDoom. Maybe the fluctuation of the frame rate is enough for the eye to notice, while with vsync on it is dead steady at 60 fps. Or maybe it is the frame rate limiter that causes it.

Re: x64 old renderer appears sluggish

Posted: Sat Nov 19, 2016 13:17
by Graf Zahl
dpJudas wrote:Interestingly, enabling vsync makes the rendering seem as smooth as with GZDoom. Maybe the fluctuation of the frame rate is enough for the eye to notice, while with vsync on it is dead steady at 60 fps. Or maybe it is the frame rate limiter that causes it.

I notice the fluctuation as well and generally consider fixed 60 fps far more pleasant than unlimited frame rate with its uneven distribution.

Re: x64 old renderer appears sluggish

Posted: Sat Nov 19, 2016 13:31
by dpJudas
It is funny how sensitive the eye is to stuff like that. I've noticed that once the FPS go beyond something like 150, then I stop noticing again. :)

Re: x64 old renderer appears sluggish

Posted: Sat Nov 19, 2016 16:39
by Nash
Eruanna: Sorry for the late reply. Here are my specs.

i7 CPU 950 @ 3.07GHz
NVidia GTX 960
15 GB DDR3