Slowdown ... CPU usage ?

[Paddywak]

Hello,
I have been running Celestia on my system for some time ... isn't it great !

I run a triple head system (3 x 19" TFT's) using the Matrox Parhelia graphics card with an effective desktop resolution of 3840 x 1024.

Celestia looks STUNNING at high res across three monitors

BUT ....

Recently I have had to do a complete system re-install and I now find Celestia is running very very slowly when I go to high res textures.
In task manager it says it is using 97-99 CPU .... ???? ....even at med res textures.
This never used to be this way ... it used to run smooth and sweet.

I have changed nothing in the reinstall ...
In fact I have re-installed a couple of times to try and sort this with out success.

Can any one help ? ... I'm sure it is something silly that I have missed.

Paddywak

My system ...
P4 2.6 GHz
1 GB RAM
3 x 19" ViewSonic TFT's
Windows XP Home - Service Pack 1
The amazing Parhelia 128MB Retail - Driver version : 1.4.1.3 (the driver I was using before the system re-install)

[selden]

Check to make sure you're actually using the manufacturer's graphics drivers. The ones provided by Microsoft do not use any hardware acceleration.

What version of OpenGL does Celestia's help menu show? v1.1 normally indicates that Microsoft's drivers are the ones being used, although I'm not sure what version Matrox is providing now. The OpenGL version number indicates which version of OpenGL the drivers are compatible with. It is not the same as the driver version number itself.

If Celestia can't keep up with your display refresh rate, it'll use all of the CPU. Check to make sure you've set the refresh rate to be 60Hz to match the flatpanels' requirements.

Does this help?

[Paddywak]

Thanks selden,
I 'm sure I'm using the Matrox drivers .... the Celestia's help menu shows :

Vendor: Matrox Graphics Inc.
Renderer: Matrox ICD for Parhelia
Version: 1.3

I'm not sure what you mean regarding the refresh rate ...
If I run the TFT's at 60 or 75Hz it makes no difference.
How do I change the refresh rate of Celestia ?

Cheers

[selden]

Paddywak,

Yes, the refresh rate makes a very big difference.
Celestia is supposed to use the refresh rate specified in the display properties menu. Some people have had problems with it switching to 60Hz when they want it to run faster, though. That may (or may not) be related to incorrect INF files.

Computer LCD flatpanels are designed to run at 60Hz and at a particular resolution. They have internal video scalers which convert the incoming video signal to the resolution and speed that they require. Trying to run them faster or at higher resolutions doesn't accomplish anything except to ensure that Celestia can't keep up.

Of course, there are other things which will prevent Celestia from running very fast. Having lots of stars being drawn (a high value of limiting magnitude) will slow things, and so will having galaxy rendering enabled while a planet or other object is in front of one. Having many objects visible at the same time will cause a slowdown, too. I try to limit my current Celestia add-ons to those I'm actually doing something with.

Does this help?

[Paddywak]

Hi selden,
Thanks again...
I understand what you are saying...
but ... as I said in my original post nothing has changed I am using the same 3 tft's at the same resolution and the same refresh rate as I was before I did the system re-install.

Celestia did work fine on my 3 tft's and at 3840 x 1024 - 60Hz - High res textures.... with lots of stars, galaxy's, night side lights, with or without time speeded up.... etc.....
Not one single problem.... it ran smooth and sweet and looked GOBSMACKING !

So.... Celestia can keep up with these settings... I'm sure its's just that I've missed something.

Thanks anyway ...

[mrzee]

Hi Paddywak,

I've had a similar issue going back a couple of months ago. In my case it turned out to be some incompatible files I had in the celestia directory. It happened because when my system went down I also upgraded to a newer version of celestia but had reminants of some older format files that it no longer liked to process. I can't remember which file(s) they were though. The other thing was my motherboard was set to safe mode while I was initialy trying to determine the problem with my crash and i'd forgotten to reset it to a useable (and safe) speed.

Best of luck,

[Paddywak]

Thanks mrzee,

I'll investigate....

[Paddywak]

Hi mrzee,
You got me on the right track ...
I started to investigate my textures... and I found that my earthnight.jpg to be corrupt I re-made it and everything is now back to...
GOBSMACKING glory.

Just a note for selden ...
My Celestia running at at 3840 x 1024 ... runs equally well at 60Hz or 75Hz ... so it seems the refresh rate is not making a very big difference.... ???

[selden]

Paddywak,

I'm sure that having a 2.6GHz system helps in that regard.