opengl is much slower than software. !#$@#¨%*(&!@$!!!!!!

[Guest]

why does zandronum run so bad? If I play the standard doom wad, it runs OK. But Sunder maps or chillax run like shit. It's slow under software and unplayable under opengl, even if I disable texture filtering and lights. Performance is also bad in many other wads (complex doom, survivalism, zdoom wars, etc)

Why is that? Doom graphics have no materials, no reflections, no shadow maps, no moving lights, etc.

[wildweasel]

The problem, if I recall, isn't graphical performance. It's that there are so many active monsters, projectiles, and the like that it is bogging down the CPU. Sunder and Chillax have some of the highest "legit" monster counts of any WAD, so it is unsurprising that they'd run so badly.

I wonder if you'd have better luck with something like prboom-plus; I seem to remember that they've massively optimized actor performance on maps with a lot of active monsters.

[VGA]

I think it has to do mostly with Intel's OpenGL support. Or at least GZDoom's renderer doesn't work very good on such hardware.

[Guest]

Does carcasses eat up the cpu? Even when all mosters are dead the performance is still low.

[VGA]

Are you using any mods like Brutal Doom?

[scifista42]

Naruto9 said:

Sunder maps or chillax run like shit. It's slow under software and unplayable under opengl, even if I disable texture filtering and lights. Performance is also bad in many other wads (complex doom, survivalism, zdoom wars, etc)

Why is that? Doom graphics have no materials, no reflections, no shadow maps, no moving lights, etc.

The wads you mentioned feature very large areas with lots of detail on screen at once, and/or very high amounts of thinkers (not only monsters, but also animated decorations and projectiles, and even moving sectors and lighting effects, see here), and/or semi-advanced graphical effects such as translucency/slopes/3D-floors. In total, their FPS-taxing effects add to each other.

[Guest]

VGA said:

Are you using any mods like Brutal Doom?

Never played any wads offline. Always played wads in multiplayer.

[scifista42]

^Which means that, in addition to all the CPU/GPU-taxing things I've mentioned above, your performance is burdened by 1) your ping and 2) netcode needing to exchange packet data about everything taking place within the map. I think you're getting performance issues on big maps and complex mods simply because the engine is overloaded by all the common computations and tasks it needs to constantly perform when handling rendering + thing AI + netcode at the same time. No wonder here.

[Graf Zahl]

Naruto9 said:

Hardware used: i3 2330m HD3000

...

Why is that? Doom graphics have no materials, no reflections, no shadow maps, no moving lights, etc.

On some decent graphics hardware this may still work - but what you have here is some integrated graphics chipset that's at the bottom end of current graphics hardware and that's known to cause performance issues with maps more complex than vanilla Doom allows. And as has been said, the map is already one of the more demanding ones, an Intel HD 3000 just cannot cope with the sheer amount of data that need to be processed.

[LexiMax]

Graf Zahl said:

And as has been said, the map is already one of the more demanding ones, an Intel HD 3000 just cannot cope with the sheer amount of data that need to be processed.

Out of curiosity, because I've been hearing this for a while - how much of this is to do with the power of the chipset, and how much does it have to do with how well HD chipsets handle OpenGL in general? The HD3000, is after all, the second most popular chipset on Steam (behind the HD4000) link, surely it must be powerful enough to play something recent.

[VGA]

The comparison to games that use normal 3d geometry isn't valid. I think the OpenGL API isn't optimised for this kind of usage.

[LexiMax]

VGA said:

The comparison to games that use normal 3d geometry isn't valid. I think the OpenGL API isn't optimised for this kind of usage.

Right, I want to know if it's this, or if it's a "Intel cards suck at OpenGL" problem.

[Graf Zahl]

The HD3000 is very clearly limited by graphics performance.

I have a HD4000 in my PC and a HD3000 in my work Mac and I have tested GZDoom on both.
While Intel's driver is clearly not as good as NVidia's, the main bottleneck with both is the graphics hardware, the HD3000 is even slow on relatively undemanding maps - but this being a Mac I cannot say how much this is caused by Apple's OS.

The HD4000 is certainly good enough to play some more detailed maps but due to lack of power it has no breathing space left if some spots are encountered when some more is needed.

Being (second) most popular on Steam doesn't mean much, it's just a bunch of users who never put a decent graphics card into their PC.

[Guest]

Is zandronum optimized for SSE, SSE2, MMX, 3Dnow?

[Graf Zahl]

That wouldn't help much. The software drawing code already is highly optimized assembly language and for the rest of the code these newfangled technologies won't do much.

If you compile the code with these features enabled or disabled will only create very minor differences.

The issue at hand is an extremely detailed and demanding map and trying to play it on a clearly underpowered machine - at least when hardware rendering is concerned.

[Guest]

How can opengl run 5x slower than software?

[Graf Zahl]

Simple: By using weak 3D hardware. The Intel HD3000 is slower than NVidia's and AMD's first generation OpenGL 3.x low end hardware.

If you plug in a real graphics card in that system you'd be surprised how much faster it is.

[Guest]

Is a hardware deaccelerator?

[Graf Zahl]

No, but it offers pathetic performance that in extreme cases can be slower than the software renderer.

[Guest]

Just made a quick test in a chillax server. Map in case was downtown and I've checked fps in that main hall with lots of Imps and Revs.

Zandronum running software and opengl.

The optimal performance is reached with 320 x 240 resolution and software render. At 1024 x 768 it's much slower, like 50 ~ 60% slower. At 640 x 480 is a bit slower than minimum res, but better to read the font.

First software: when looking at a wall in a cubic room with rocket boxes, fps can go over 600 (wow). In the huge hall with Imps and Revs (all were standing, there were no players and I was spec), fps was around 43.

Then opengl: at least 50% performance hit. In the cubic room the hit is massive, from over 600 under software to around 70 under opengl.

So resolution, how wide open is the map and how many sprites are on screen at once have a huge impact on fps.

[Edward850]

Naruto9 said:

So resolution, how wide open is the map and how many sprites are on screen at once have a huge impact on fps.

How long is a piece of string?

[Maes]

Naruto9 said:

How can opengl run 5x slower than software?

This has been brought up countless of times in the past. In layman terms, the hardware is overwhelmed or "Zerg rushed" by thousands of requests per frame, especially for drawing sprites. Doom maps don't have much in terms of geometry/mesh details, but they are egregiously unsuitable/hard to convert to an optimized 3D mesh that will be easily handled by modern 3D hardware. In addition, asking to draw a few hundred sprites per frame on top of that, is really anomalous, and creates a lot of overhead simply by performing so many separate operations.

Thus, it's not unusual that OpenGL might be outperformed by software if the penalties/overheads incurred in rendering a particular scene are particularly high. Of course, some video cards/drivers might be better than others in this aspect, but Intel is really bottom of the line all the way, no matter how better the HD line is compared to the archaic GMA one.

Naruto9 said:

Does carcasses eat up the cpu? Even when all mosters are dead the performance is still low.

Yes, even dead monsters, pick-up bonuses and even some decorations and unseen entities still count as thinkers and consume some CPU cycles each frame, and of course they cost just as much to render when they are on-screen as any other monster or decoration. It's not trivial to economize CPU cycles by removing them from the list of thinkers without also introducing other side effects.

Naruto9 said:

Is the HD3000 a hardware deaccelerator?

You could say that in some cases, yeah. In the past, the S3 chipset was accused of the same thing: the hardware implementation was so bad, that it was often faster to do things purely by software. This was even more true of the older Intel chipsets, which had no 3D acceleration at all: it was all done in software, and it was not hard to write your own software renderer that could outperform Intel's "OpenGL" one ;-)

[Graf Zahl]

Maes said:

but Intel is really bottom of the line all the way, no matter how better the HD line is compared to the archaic GMA one.

It must be said that this is correct for HD3000.
The HD4000+ are at least comparable with first generation OpenGL3/DirectX 10 hardware and should be sufficient for most tasks. Still, if you got the money to afford a $50 entry-level graphics card, it should still easily outpace the integrated chipset.

[snapshot]

Naruto9 said:

Hardware used: i3 2330m HD3000

why does zandronum run so bad? If I play the standard doom wad, it runs OK. But Sunder maps or chillax run like shit.

Same here, Unfortunately there's no solution for this (Unless you decrease the amount of Monsters,projs ... etc on maps) .

[boris]

Graf Zahl said:

Being (second) most popular on Steam doesn't mean much, it's just a bunch of users who never put a decent graphics card into their PC.

Is it known how Steam counts the GPUs? I mean, does it not count the the Intel HD graphics if there's a dedicated GPU in the PC?

[GooberMan]

I'd imagine it prefers the primary graphics adapter since that's what games prefer.

[Maes]

GooberMan said:

I'd imagine it prefers the primary graphics adapter since that's what games prefer.

I only owned a Win8 dual-GPU laptop for a short stint, and I recall that at least ZDaemon and GZDoom used the Intel HD, while getting them to use the "good" stuff required some fucking around with a special menu.

[VGA]

Maes said:

I only owned a Win8 dual-GPU laptop for a short stint, and I recall that at least ZDaemon and GZDoom used the Intel HD, while getting them to use the "good" stuff required some fucking around with a special menu.

http://zdoom.org/wiki/CVARs:Display#Video_adapter
I never had to use those cvars and commands myself, but since it's relevant ...

[kb1]

Maes said:

Yes, even dead monsters, pick-up bonuses and even some decorations and unseen entities still count as thinkers and consume some CPU cycles each frame, and of course they cost just as much to render when they are on-screen as any other monster or decoration. It's not trivial to economize CPU cycles by removing them from the list of thinkers without also introducing other side effects.

Just a side note: For the software renderer, the absolute worst sprite case is when sprite overdraw occurs (sprites drawn on top of one another). Doom's normal rendering method wreaks havoc on the system's memory caches, to the point where each pixel causes a cache flush. But, overdraw makes the previous cache writes invalid, which slows down the pipeline to it's worst. Just the act of walking up close to a large pile of bodies can cause an otherwise smooth display to stutter.

But OpenGL works differently.

[snapshot]

I just got an NVidia GTX670 and it works super smooth now .