Author Topic: Some research into fps droppage  (Read 1265 times)

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Offline Col. Fishguts

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Some research into fps droppage
Like some other people I have perfomance problems with 3.6, which weren't present with the older HTL builds.
Specifically, I get huge fps drops when facing a capship that jumped in late in the mission.
So I did some testing with the 4th (?) mission, "A Lion at the door', where near the end a Orion and a Sobek jump in ....looksie for yourself.

My hardware specs: AthlonXP 1900, GF Ti4200 with 64 MB RAM, 512 MB DDR RAM

1) fs2_open_3.6, flags: -glow -spec, only mv_core.vp
no other extra art used, especially no shinemaps used, only the stock [V] ones
What I get:


NOTE: The numerous red timerbars are misleading, since they seem to be caused by taking the screenshot. What I actually saw, when facing the Orion, were about 4-5 white bars, which is rather strange, compared to the second test.

2) RT's newer 3.6 with the fancy pcx compression (from this thread).
-glow -spec -pcx2dds, mv_core.vp and mv_shine.vp (so actually more textures to load into the video card).
And look, what happens in the same situation:



So, what is going on in the first test without pcx compression ?
It says I still have 14 MB free Texture memory, but I don't know if that's correct, since at the beginning of the mission it says 72 MB free, but my card only has 64 MB ?!?

The funny part is, that this effect is rather unaffected by fancy new hires or high-poly stuff, but more of when something is loaded.
And the fact that removing the mv_shine.vp hasn't a effect is rather confusing. Does the engine make internal copies of the diffuse map for use a spec map, instead of using it directly ?
Anyway, i hope a coder can have a look at the memory usage and understand a bit more than I do.
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Offline RandomTiger

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Some research into fps droppage
Ignore the timerbars, they are for coder use and could be set to a different configuration in each exe.

The texture memory as reported in these stats is a combination of video and system ram as D3D sees it avaliable for storing textures.

All textures in fs2_open are stored once in video and once in texture memory.

Your pause with ships entering late is either a texture caching bug or you are running out of texture memory. Most likely the latter if you are using extra art witha 64MB card.

Compressed pcx reduces the size of both the system and video memory copys of the texture.

 

Offline Col. Fishguts

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Some research into fps droppage
So I can run out of video memory only by using glowmaps as extra art ?
Does it use the same amount of memory to use specific shinemaps, as it does when only using standard maps with the -spec flag ?
"I don't think that people accept the fact that life doesn't make sense. I think it makes people terribly uncomfortable. It seems like religion and myth were invented against that, trying to make sense out of it." - D. Lynch

Visit The Babylon Project, now also with HTL flavour  ¦ GTB Rhea

 

Offline Kosh

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Some research into fps droppage
Quote
since at the beginning of the mission it says 72 MB free, but my card only has 64 MB ?!?



I have that same thing with my laptop. It says that I have over 100 megs free when I only have a 16 meg mobility card.
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Offline Col. Fishguts

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Some research into fps droppage
Hmm...this yelds some questions:

- What does the engine exactly do, if it runs out of video memory ? (obviously it's something that slows down the game)

- If a ship is destroyed (so it's no longer rendered), is the memory which is used by its textures freed ?
Since when looking at the "texture mem free" while playing, it only goes down, never up.
« Last Edit: June 28, 2004, 04:05:57 pm by 1445 »
"I don't think that people accept the fact that life doesn't make sense. I think it makes people terribly uncomfortable. It seems like religion and myth were invented against that, trying to make sense out of it." - D. Lynch

Visit The Babylon Project, now also with HTL flavour  ¦ GTB Rhea