Celestia and processor usage

[jliechty]

Celestia 1.2.4 is running ok on my 800MHz AMD Duron machine with 256MB of RAM and an ATI Radeon VE (32 MB RAM). However, whether it runs in a reasonably sized window, or an 800x600x16bit or 32bit resolution full-screen, it always seems to be running at a very low frame rate (i'm guessing it averages 20-30 or something, but sometimes it will skip a few, and it's very noticable). It also always runs at 99% CPU utilization.
Thus, I'm wondering if, since I'm due for an upgrade of some kind anyway, I should upgrade the CPU or the video card. Or is there something I can do to make Celestia run better w/o spending any money?

[guest]

That's odd. I have an older P3-500, also with 256mb RAM; but a 64mb GeForce card. Celestia runs smooth as silk - usually at 1024 x 768 x 32. I'm just going by the visual; as I've never checked the frame rate. Do you have anything running in the background?

[jliechty]

That's odd. I have an older P3-500, also with 256mb RAM; but a 64mb GeForce card. Celestia runs smooth as silk - usually at 1024 x 768 x 32. I'm just going by the visual; as I've never checked the frame rate. Do you have anything running in the background?

No, there are not any other normal priority tasks running (although I do have Folding@Home running, but according to the task manager it's not getting any power, since Celestia.exe is always at 99% usage). I'm thinking that my since my crappy Radeon VE doesn't implement as many acceleration features as the newer GeForces (3/4), that the CPU is being forced to make up for what is lacking, and that might be part of the problem. Does that sound reasonable? Any other ideas?

[Doug]

No, there are not any other normal priority tasks running (although I do have Folding@Home running, but according to the task manager it's not getting any power, since Celestia.exe is always at 99% usage). I'm thinking that my since my crappy Radeon VE doesn't implement as many acceleration features as the newer GeForces (3/4), that the CPU is being forced to make up for what is lacking, and that might be part of the problem. Does that sound reasonable? Any other ideas?

I've noticed on my Linux box that Celestia grabs 100% of the CPU, even if nothing is really happening, like when you have the time setting at real time.

[jliechty]

I've noticed on my Linux box that Celestia grabs 100% of the CPU, even if nothing is really happening, like when you have the time setting at real time.

Hmm, even when I pause the time, it still sticks at 99% usage. Maybe it's time for a new gfx card after all

[chris]

It's not your card . . .
Celestia isn't very friendly about processor usage . . . Even when the camera isn't moving and time is paused, it still keeps rendering frames. I should probably fix that :>

--Chris

[jliechty]

Well, the 100% processor usage isn't really the problem. The problem is that when moving around in the solar system (and elsewhere), the graphics stutter. I don't really know how else to describe it, but only to say that it's not smooth. Thus I was trying to figure out which component would be more beneficial to upgrade - the CPU or Video card.

[Guest]

I too got 99% processor usage, even with my AMD XP 1800+. Stuttering only occurs when i'm getting close to planets, then i notice that some frames are skipped.

[jliechty]

I too got 99% processor usage, even with my AMD XP 1800+. Stuttering only occurs when i'm getting close to planets, then i notice that some frames are skipped.

What kind of video card do you have paired with that Athlon XP?

[Matt McIrvin]

On some systems there will be a noticeable stutter when approaching a planet because the computer is busy loading the planet texture into the 3D hardware.

I have heard it claimed that modern Macs stutter more when loading textures than PCs (at least, the makers of the Diablo games used this as an excuse for a performance problem). But in the case of Celestia it sounds as if many PC users see the same pause that I do on my Mac.

Under normal conditions (that is, not using Bruckner's monster asteroid file!) I get 20-30 FPS flying around the solar system at 1152x870x32 on a dual 1GHz G4 Mac with a Radeon 7500, except for the occasional texture-loading stutter. As I speculated elsewhere, the video hardware is probably more important than the CPU; I wouldn't be surprised if Chris gets better frame rates on his 933 with a GeForce 4MX.

This drops to about 15-20 FPS if I turn on galaxy rendering, and of course it's possible to make it lower by turning on the display of absolutely everything and zooming out to a fisheye view.

I also tried running Celestia at 1920x1080, the highest resolution my card and monitor will allow (albeit not very usably). Surprisingly, it's almost as fast even then, except when I get close to Earth with its complex texture-- then it drops abruptly to about 10 FPS. Probably the best resolution for Celestia is 1280x1024, though the 60Hz flicker on my old monitor makes it not good for much else.

[Matt McIrvin]

Hmm, now it's reporting much higher frame rates (above 50 fps) flying around Mars at 1152x870. I suppose it varies a lot depending on demand. Pretty smooth, in any event...

[Kendrix]

Have you installed the VIA drivers on your PC ? (the AllInOne 4.39 beta)

Without them you could run something like 3 times slower than normal !

[jliechty]

Have you installed the VIA drivers on your PC ? (the AllInOne 4.39 beta)

Without them you could run something like 3 times slower than normal !

I have the VIA 4in1s version 4.38. Are the new betas worth upgrading to from that?

[marshead]

A related problem I am still having is that when I go to a ringed planet (like Saturn or Uranus), the frame rate drops precipitously when panning and rotating around those planets. Typically, the closer and the more of the rings that are showing (i.e. more face on), then the slower it runs. When zooming or rotating, it will drop to ~1 FPS, and at times, less.

I did not have this problem with 1.2.2 (but did starting with 1.2.3). I reported it to the bugs section, but I am still having MANY problems with this. Does anyone have any thoughts or suggestions on what might be happening???

Marshead

OK, so it may not be 100% on topic for this section, but it seems closely related enough that I thought I'd bring it up again.

[grylor]

If you will upgrad to 2GHZ or stronger CPU it does not matter, because Celestia runs as real time rendering using all available CPU time and GPU. Animations will be smoother but usage will be 99% :) Its a tax for realtime rendering and position computeing. If you stop time the usage remains, because you can move camera around object. Again realtime.

enjoy.

grylor

[Mikeydude750]

On some systems there will be a noticeable stutter when approaching a planet because the computer is busy loading the planet texture into the 3D hardware.

I have heard it claimed that modern Macs stutter more when loading textures than PCs (at least, the makers of the Diablo games used this as an excuse for a performance problem). But in the case of Celestia it sounds as if many PC users see the same pause that I do on my Mac.

Under normal conditions (that is, not using Bruckner's monster asteroid file!) I get 20-30 FPS flying around the solar system at 1152x870x32 on a dual 1GHz G4 Mac with a Radeon 7500, except for the occasional texture-loading stutter. As I speculated elsewhere, the video hardware is probably more important than the CPU; I wouldn't be surprised if Chris gets better frame rates on his 933 with a GeForce 4MX.

This drops to about 15-20 FPS if I turn on galaxy rendering, and of course it's possible to make it lower by turning on the display of absolutely everything and zooming out to a fisheye view.

I also tried running Celestia at 1920x1080, the highest resolution my card and monitor will allow (albeit not very usably). Surprisingly, it's almost as fast even then, except when I get close to Earth with its complex texture-- then it drops abruptly to about 10 FPS. Probably the best resolution for Celestia is 1280x1024, though the 60Hz flicker on my old monitor makes it not good for much else.

DROPS to 10 FPS?! Damn, you're lucky you got a nice computer. My computer can do about 15 FPS MAX anywhere in the Sol system(even without the monster asteroid data files).

Plus, my monitor's max resolution is 1024x768, so you're lucky in that section.

Of course, that'll all change when I start building my new computer. Then I'll be screaming thru like nobody's business =P

[chris]

A related problem I am still having is that when I go to a ringed planet (like Saturn or Uranus), the frame rate drops precipitously when panning and rotating around those planets. Typically, the closer and the more of the rings that are showing (i.e. more face on), then the slower it runs. When zooming or rotating, it will drop to ~1 FPS, and at times, less.

I did not have this problem with 1.2.2 (but did starting with 1.2.3). I reported it to the bugs section, but I am still having MANY problems with this. Does anyone have any thoughts or suggestions on what might be happening???

Marshead

I thought that I fixed this in 1.2.4 . . . Is your graphics card a Rage 128? Also, does the slowdown occur when you view eclipses, too? Make absolutely certain that you're running 1.2.4 (and *not* one of the 1.2.4 prereleases) . . . If you are, it means I'll have to revisit this issue.

--Chris

[marshead]

Chris,

Yes it is a Rage 128. Yes I do get a pretty massive slowdown when shadows are on, but only when the shadow falls on a planet (or planet shadow on satellite).

I am also 99.999% certain that I am running 1.2.4 and not one of the pre-releases. If ther is anyting I can do to test to help out, let me know! Otherwise, absolutley stunning as always!

Marshead

[Matt McIrvin]

DROPS to 10 FPS?! Damn, you're lucky you got a nice computer.

Given what I paid for it, it better be!

But I doubt I needed this much computer to get good performance with Celestia, since with modern video cards it's the 3D hardware that will do all the heavy lifting, unless you're doing something extreme like playing with enormous textures or 7000 asteroids. For the same reason, PC vs. Mac differences are not really an issue most of the time.

Just yesterday I spent some time playing around with enormous textures to see how well I could do. It's possible to make really nice 2048x1024 textures for the Galilean moons by scaling up Bjorn Jonsson's maps just a little. The results were pretty much what you'd predict from the amount of video RAM I have (32 MB); it can do just fine with a single body bearing a 2048x1024 texture, but as soon as two get in frame, it cries uncle and surrenders to the CPU, and then the computer really gets a workout!

I think this card supports some kind of texture compression, but I didn't get into playing with that.

[chris]

I think this card supports some kind of texture compression, but I didn't get into playing with that.

It does, but on my GF4MX at least, texture compression doesn't seem to be exposed on the OS X drivers. Need to look into this some more . . .

--Chris