S-l-o-w

SDL Development
1

Hi!

I have Redhat 7.3 system, with 512megs of RAM and Geforce 4 MX 440 video
accelerator.

I have donwloaded Mesa and a SDL-OpenGL program (linuxssn) - the mesa OpenGL
demos seem to run at a reasonable rate, but the SDL-OpenGL program runs at
about two seconds per frame.

Any idea how I can speed the program up? I am a relative Linux newbie - I
heard you can “renice” a process to give it more time on the processor? How
can I find what is “robbing” CPU time from my SDL program?

Thanks!–
Stefan Viljoen
Polar Design Solutions
Software Support Technician

2

why are you using mesa instead of regular opengl? Just wanted to make sure
you know that mesa is all software rendered (slow) while regular gl uses
your video card’s acceleration features (faster!).

you probly already knew that but just making sure!> ----- Original Message -----

From: rylan@intekom.co.za (Stefan Viljoen)
To:
Sent: Tuesday, February 24, 2004 2:27 PM
Subject: [SDL] S-L-O-W

Hi!

I have Redhat 7.3 system, with 512megs of RAM and Geforce 4 MX 440 video
accelerator.

I have donwloaded Mesa and a SDL-OpenGL program (linuxssn) - the mesa OpenGL
demos seem to run at a reasonable rate, but the SDL-OpenGL program runs at
about two seconds per frame.

Any idea how I can speed the program up? I am a relative Linux newbie - I
heard you can “renice” a process to give it more time on the processor? How
can I find what is “robbing” CPU time from my SDL program?

Thanks!

Stefan Viljoen
Polar Design Solutions
Software Support Technician

SDL mailing list
SDL at libsdl.org
http://www.libsdl.org/mailman/listinfo/sdl

3

— Stefan Viljoen wrote:

Hi!

I have Redhat 7.3 system, with 512megs of RAM and
Geforce 4 MX 440 video
accelerator.

I have donwloaded Mesa and a SDL-OpenGL program
(linuxssn) - the mesa OpenGL
demos seem to run at a reasonable rate, but the
SDL-OpenGL program runs at
about two seconds per frame.

Mesa is a software only version of OpenGL. If you want
hardware acceleration, you’ll need to install DGA
drivers (and probably upgrade XWindows if on RH 7.3 to
support DGA). Fortunately, nvidia has such drivers.
You’ll want to uninstall Mesa before installing their
drivers.

Any idea how I can speed the program up? I am a
relative Linux newbie - I
heard you can “renice” a process to give it more
time on the processor? How
can I find what is “robbing” CPU time from my SDL
program?

Well, there probably isn’t anything robbing your CPU
time, just your CPU having trouble rendering OpenGL
scenes using only software (read: icky slow,
especially with alpha transparency or anything like
that).

If you want, you can try “ps” and “ps -A” which should
give you a list of processes and how much CPU time
they’ve used (you’ll probably want to do “ps -A |
more” as the list is large using -A for all)

renice dosn’t exactly ring a bell… ‘nice’ is a
program (and a measure) which allows processes to be
’nice’ and be less important. Renice I assume undoes,
or is the opposite of that.

This may cause system instability in some
circumstances, it’s akin to changing the priority of a
task using the task manager. Just an FYI.

  -Mike> Thanks!

–
Stefan Viljoen
Polar Design Solutions
Software Support Technician

SDL mailing list
SDL at libsdl.org
http://www.libsdl.org/mailman/listinfo/sdl

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4

Stefan Viljoen escreveu:

Hi!

I have Redhat 7.3 system, with 512megs of RAM and Geforce 4 MX 440 video
accelerator.

Are you sure you have hardware acceleration? Have you downloaded and
installed the NVidia drivers?

[]s

Adilson.–
Nullum magnum ingenium sine mixtura dementiae fuit - Seneca

5

“Alan Wolfe” wrote:

why are you using mesa instead of regular opengl? Just wanted to make
sure you know that mesa is all software rendered (slow) while regular
gl uses your video card’s acceleration features (faster!).

/me wonders wtf a regular opengl could be. it seems you’re a little bit
confused about what mesa is and where it gets used. from the mesa
homepage:

The DRI architecture, originally developed by Precision Insight, Inc.
uses Mesa and provides hardware acceleration for a number of popular
chipsets.

The DRI is part of XFree86 4.0 and later.

If you download and install XFree86 4.x you do not need to install Mesa
separately. All the important parts of Mesa will be installed with the
rest of XFree86.

though, the nvidia drivers come with their own libGL.

clemens

6

as far as ive ever heard, mesa is a project to do everything opengl can do,
but use software rendering for it.

does it just fall back on software if supporting hardware is present? im not
sure about that one.> ----- Original Message -----

From: clemens@thf.ath.cx (Clemens Kirchgatterer)
To:
Sent: Wednesday, February 25, 2004 10:31 AM
Subject: Re: [SDL] S-L-O-W

“Alan Wolfe” <@atrix2> wrote:

why are you using mesa instead of regular opengl? Just wanted to make
sure you know that mesa is all software rendered (slow) while regular
gl uses your video card’s acceleration features (faster!).

/me wonders wtf a regular opengl could be. it seems you’re a little bit
confused about what mesa is and where it gets used. from the mesa
homepage:

The DRI architecture, originally developed by Precision Insight, Inc.
uses Mesa and provides hardware acceleration for a number of popular
chipsets.

The DRI is part of XFree86 4.0 and later.

If you download and install XFree86 4.x you do not need to install Mesa
separately. All the important parts of Mesa will be installed with the
rest of XFree86.

though, the nvidia drivers come with their own libGL.

clemens

SDL mailing list
SDL at libsdl.org
http://www.libsdl.org/mailman/listinfo/sdl

7

Alan Wolfe wrote:

as far as ive ever heard, mesa is a project to do everything opengl can do,
but use software rendering for it.

does it just fall back on software if supporting hardware is present? im not
sure about that one.

you’re right.
people use to be mistaken about this. OpenGL is a standard, that does
not concerns about hw acceleration. GPU vendors do your own libraries,
using OpenGL standards, but using their GPUs instruction sets.
Some versions ago Mesa has code for glide-base hardware, but hasn’t
anymore…