GZDoom Performance Problem

[Graf Zahl]

Randy brings out one important issue. What's your FSAA settings in GZDoom? (gl_vid_multisample or forced settings in the driver)

What happens when you change these settings?

[TIHan]

I have "Use application settings" for AA and AF. I never use AA because it is not really noticeable at high resolutions such as 1920x1080. My Catalyst AI is at standard, but when set to high and none, no change in FPS.

I tried gl_vid_multisample by setting to 8(0 was already there by default), I saw no change in FPS when I rebooted GZDoom with this setting. I tried gl_vid_compatibility set to true and no change in FPS.

Is there anything else I can check?

[Graf Zahl]

No. You did enough. It clearly shows that the bottleneck is not in the rasterization stage but somewhere else.

I'd really like to see some results of this map from some other ATI users.

[randi]

But what about GZDoom Hellcore 2.0 Map09 right at spawn at 1920x1080?

With revision 548, 27-28 FPS. But wait! It gets even better! At the larger resolution of 2048x1536, I get 37-38 FPS. In fact, the speeds depend entirely on the aspect ratio of the mode set and not the size. All 4:3 modes are 37-38 FPS. All 16:9 modes are 27-28 FPS. And all 16:10 modes are 30-31 FPS.

[TIHan]

But what about GZDoom Hellcore 2.0 Map09 right at spawn at 1920x1080?

With revision 548, 27-28 FPS. But wait! It gets even better! At the larger resolution of 2048x1536, I get 37-38 FPS. In fact, the speeds depend entirely on the aspect ratio of the mode set and not the size. All 4:3 modes are 37-38 FPS. All 16:9 modes are 27-28 FPS. And all 16:10 modes are 30-31 FPS.

I have noticed this too. It makes sense because the widescreen aspect ratio draws more than the 4:3 aspect ratio. That's weird you get lower frames than mine and you have the brand new ATI card that has been released.

[Graf Zahl]

This map really is one of the worst designed maps for a hardware renderer which I ever encountered. In the main village area there's not one single one-sided linedef that may block the view. So I have to process everything that's in the field of view and draw it. What I don't understand is why the rendering itself takes twice as long on new ATI cards than on my 2 year old GF 8600. I get 47 fps in 1280x1024 at the starting point.

Maybe it's just that this map brings out the worst in the driver for some reason. It almost looks like it doesn't manage efficient z-culling and processes every hidden pixel.

Please recheck this when I upload the next beta later today. I'm going to add a new CVAR 'gl_sort_textures'. Try setting this to 0 and see if it makes any difference.

[TIHan]

For fun, I changed "Textures Enabled" to false in OpenGL options, and my frames shot up to 45fps. 34-37FPS right up to 45FPS is a quite a boost. Obviously my card shouldn't have any problem with having textures being rendered as I have 2GB of video memory.

I'll also wait till you upload your next build and I will test and see what "gl_sort_textures" does for me.

[Graf Zahl]

Texel fetch also costs time as it requires memory access. When I do that I get framerates above 50 easily in that map. 45 fps is still very low considering that nothing special is being done.

[TIHan]

I just tried your new beta build with "gl_sort_textures". I set it to "0" or "false" and my FPS right at spawn went down to 22fps.

[Graf Zahl]

Ok, so this is even more useless on ATI than it is on NVidia. Well, it was worth a try at least.

[Graf Zahl]

I started another round of benchmarks:

http://forum.drdteam.org/viewtopic.php?f=22&t=4518

Like always I am still missing some info for modern ATI cards. If you want to help me please do this once and send me the results.

[TIHan]

Give me till the end of the week to post benchmarks. I'm really busy with work and school at the moment.

[Graf Zahl]

Ok, no problem. I have found one thing though which would explain why you had a performance loss between 1.2.1 and the more recent version. I'll upload that new build this evening. Let's see how that works out.

[Lioyd_Irving]

...So there actually was a command to show the framerate the whole time ?!

Oh, uh...I'm just passing by. Go on, don't mind me.

[Graf Zahl]

...So there actually was a command to show the framerate the whole time ?!

The entire whole time since ZDoom has emerged from the stone age!