FPS rates low when Celesia starts with high res

[cartrite]

This is related to what fsgregs reported in the Users Forum. When I start Celestia with texture resolution set to high, I get really slow frame rates as compared to when I start Celestia with texture resolution set to medium. When I start Celestia with texture resolution set to high, fps rates will remain very low even though texture resolution is set to medium while running. Here are some screen shots that illustrate that point. This may be a driver bug or something but it seems to affect some users so maybe they will see this and try setting texture resolution to medium before exiting Celestia.. It may also be GPU class specific. ie Nvidia GeForce cards <= 8600, <=9600, etc.

Before I took these next two screen shots, I ran Celestia, set texture resolution to high, and exited Celestia. My setting for texture resolution set to high was saved.

high-on.jpg

high-on-1.jpg

Before I took this screen shot, while I was running Celestia to take the above screen shots, I set texture resolution to medium, and exited Celestia. My setting for texture resolution set to medium was saved.

high-off.jpg

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[selden]

I'm sure you're aware of this, but ...
How long did you wait after changing resolutions?
Celestia's fps display takes more than 10 seconds to stabilize on my system.

[cartrite]

I'm sure you're aware of this, but ...
How long did you wait after changing resolutions?
Celestia's fps display takes more than 10 seconds to stabilize on my system.

If I start Celestia KDE with high resolution textures, I'm stuck with slow fps rates until I set texture resolution to medium and exit. Then after restarting Celestia, fps rates return to normal.

Also, this is not just about the fps display. When I start Celestia set to high texture resolution the startup.celx script I run when Celestia starts lags and jumps while the script is running. If I speed up time, there are also jumps and lags. Same happens when I try to rotate the earth with the mouse. These frame rates are really low. I should also add that this problem is intermittent. That is when the fps is abnormally low, they will stay low until I reset and exit the program. But sometimes fps rates are normal even when I start Celestia with highres textures on. So some unknown factor is probably also contributing to this.
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[t00fri]

Steve,

what are these horrible artefacts on your images above?

Also, what do you mean exactly with setting high texture resolution? SHIFT+R or what? You are not referring to any settings on your graphics driver/Xserver?

Probably you have activated Sync to VBlank, whence the highest possible fps rate equals the refresh rate of your LCD monitor. Which seems to be reflected by the 60 fps you got in medium resolution.


Fridger

[cartrite]

Steve,

what are these horrible artefacts on your images above?

I think your are referring to my incomplete cloudmap here. I am trying to build a new cloudmap with modis daily images. From day 2 day, modis imagery has gaps near the equator and overlaps near the poles because of the resolution of the camera and the polar orbit it travels.

Also, what do you mean exactly with setting high texture resolution? SHIFT+R or what? You are not referring to any settings on your graphics driver/Xserver?
I set texture resolution to high in KDE version via Settings => Configure Celestia => Textures Resolution: High. Typing SHIFT+R or R no longer works in the SVN versions. Chris disabled that keyboard control.

Probably you have activated Sync to VBlank, whence the highest possible fps rate equals the refresh rate of your LCD monitor. Which seems to be reflected by the 60 fps you got in medium resolution.
Yes I activated that. But I'm not concerned with getting fps above 60. I'm concerned with fps below 60. Like fps=12 of the first 2 images I posted.


Fridger

[t00fri]

I'm sure you're aware of this, but ...
How long did you wait after changing resolutions?
Celestia's fps display takes more than 10 seconds to stabilize on my system.

If I start Celestia KDE with high resolution textures, I'm stuck with slow fps rates until I set texture resolution to medium and exit. Then after restarting Celestia, fps rates return to normal.

Also, this is not just about the fps display. When I start Celestia set to high texture resolution the startup.celx script I run when Celestia starts lags and jumps while the script is running. If I speed up time, there are also jumps and lags. Same happens when I try to rotate the earth with the mouse. These frame rates are really low. I should also add that this problem is intermittent. That is when the fps is abnormally low, they will stay low until I reset and exit the program. But sometimes fps rates are normal even when I start Celestia with highres textures on. So some unknown factor is probably also contributing to this.
cartrite

Steve,

I followed your procedure exactly, but all framerates are exactly the same as I would have expected. The only way one could understand your effect perhaps is that there is some hidden add-on or some textures that make things VERY slow in hires, even though they are practically invisible in the initial field. That would mean that somewhere the culling does not work as it should. But I am unaware of anything that could possibly matter in this respect.

Did you try what happens if you run with empty hires and extras folders?

Fridger

[cartrite]

I doubt that testing this with an empty hires or extras folder would produce the affect.

For the test I ran today, I did have many textures in the hires folder that are 8k. For earth an 8k rgba, 8k normalmap, and the cloud vt were loaded at startup when textures were set to high.

What is surprising here is that I can switch medres to hires textures on after starting Celestia with medres files and not affect the fps. But I couldn't switch hires to medres after Celestia started with hires textures and get an increase in frame rates. The frame rates stayed low.

I think this may have something to do with the graphics card's memory is not being cleared. I know that Celestia doesn't clear ram or virtual ram, but I thought it was clearing the graphics card's memory. Also, as I said in a earlier post, this problem is intermittent. Sometimes it happens and sometimes it doesn't. But when it does happen, I'm stuck with slow frame rates until I restart Celestia with medres textures. This has always cleared up the problem.

Also, this is not new. This has been happening for over a year now. I know I brought this up before. I can't remember if anyone gave me an answer though. But for now, my workaround always seems to work. I only brought it up again because of what Frank and Bob posted in the Users Forum.

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[selden]

What other objects are in the field of view?
If some of them have hires textures associated with them, that would cause a slowdown.
It'd seem to be intermittant because sometimes they'd be outside the field of view.

[t00fri]

What other objects are in the field of view?
If some of them have hires textures associated with them, that would cause a slowdown.
It'd seem to be intermittant because sometimes they'd be outside the field of view.

My saying (cf. my last post), didn't you notice?

...some hidden add-on or some textures that make things VERY slow in hires, even though they are practically invisible in the initial field. That would mean that somewhere the culling does not work as it should.

Fridger

[cartrite]

What other objects are in the field of view?
If some of them have hires textures associated with them, that would cause a slowdown.
It'd seem to be intermittant because sometimes they'd be outside the field of view.

According to the screen output, nothing extra is getting loaded except the moon and the bumpmap for it. I renamed the 2k moon textures in hires so the medres are loaded but that has no affect. Frame rates are still low.
The screen output says I load gstar.jpg from the medres folder, flare.jpg and logo.png from the textures folder, earth.png, earth-norm.png from hires folder, and level0 cloud tiles. Earth.png and earth-norm.png are both 8k textures. That is causing the load. But I CAN run those 2 textures at 60 fps when I start Celestia with medres textures and then switch to hires while Celestia is running. If I start Celestia with hires, fps <=12, even if I change back to medres textures. That is until I exit.
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[cartrite]

How Does Celestia decompress png files on Linux? With the system libpng? I think that this is causing the problems for my card.
I tried a little experiment. So far this morning, this drop in frame rates has happened when I load the 8k png earth files. So I tried nvcompress to compress them with bc3 and bc3n formats. I did these with and without mipmaps. Both give the 60 fps rates when I start Celestia with those files loaded at startup. I'll have to use these for a while to see if the problem ever comes back but I already tried to load the png files again after running the 2 sets of dds and dxt5nm files, and the frame rates did drop to 12 again.

Actually, It doesn't seem to be a decompression thing. I just saved the png files with 0 compression and Celestia still has low fps rates when it starts with them.
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[chris]

I suspect that this difference in frame rates may have something to do with where textures are being allocated in memory. If they're located in onboard graphics memory, rendering will be very fast. But, when onboard memory fills up, the textures have to be placed in system memory. This is much slower because the GPU has to read texture data across the PCI bus. You probably don't see the problem with DDS compressed textures because they're small enough that graphics memory never fills up.

To fix the problem, we need to implement some strategy for managing textures. Textures that haven't been used recently should be relocated from onboard graphics memory to system memory (or evicted from memory completely.)

--Chris