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CobyWalkerGames

OpenGL OpenGL Questions

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Windows XP,OpenGL,Glut,CV++ Express I have a simple program and its running slow. I have a Nvidia Geforce 8800 GT. Does OpenGL use the graphics card or just the processor? Also I have a AMD Phenom x4 Quad core processor whats with the slow framerate? Is OpenGL OLD/outdated? If so whats better? [ Please don't wackily punctuate your topic lines. --Sneftel ] [Edited by - CobyWalkerGames on August 18, 2008 1:36:07 PM]

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1) More like the GPU (graphics card) uses OpenGL
2) If it's running using OpenGL, it should not be too dependent on what type of processor you're using, since it's the GPU that's running it.
3) There really is no 'old' for OpenGL, at least the way you state it. OpenGL .000000001 would still accelerate any programs using it just fine.

FlyingIsFun1217

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Quote:

Does OpenGL use the graphics card or just the processor?

Both, to some degree anyway. But if you do it right you can get the graphics card to do most of the work. Immediate mode places slightly higher processor overhead due to the number of function calls made, but you can still get huge framerates on simple games that way.

Quote:

Also I have a AMD Phenom x4 Quad core processor whats with the slow framerate?

That depends heavily on your program itself, not necessarily the processor. Note that if your program is single threaded, then you are limited to the speed of a single core. That said - a single core would work well for lots of games which aren't trying to squeeze every last drop from the hardware.

Quote:

Is OpenGL OLD/outdated?

Arguably, yes and no. Practically speaking, if you are using GLUT then it will probably be more than fast enough for whatever you are doing.

The slow frame rate probably has a simple answer, but we would need to see your program to diagnose the issue.

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OpenGL is an API which does not say anything about GPUs and CPUs. It's the implementation of the API that matters. There are hardware implementations and software implementations (like Mesa). If your drivers, etc are set up correctly, it should run on hardware and thus be quite fast.

If you suspect that you're not getting the performance you should, check your driver, compiler, etc setup. The problem may be in your program, too.

OpenGL is old, but not necessarily outdated. There is a lot of legacy in OpenGL, but if you use the "modern" subset (VBO's, shaders, FBO's, etc), you should be fine off. If your project is going to be Windows only, you can use DirectX instead of OpenGL. If you're on a Mac or Linux box, you have no alternatives to OpenGL.

-Riku

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Quote:
Original post by CobyWalkerGames
Windows XP,OpenGL,Glut,CV++ Express

I have a simple program and its running slow.
I have a Nvidia Geforce 8800 GT.

Does OpenGL use the graphics card or just the processor?

Also I have a AMD Phenom x4 Quad core processor whats with the slow framerate?

Is OpenGL OLD/outdated? If so whats better?


[ Please don't wackily punctuate your topic lines. --Sneftel ]


You issue is most like due to something in your system or in your code, you might not have graphics drivers installed, or getting a software only opengl context, or hit a software fallback within your driver.

Anyway, you need to post the relevant code and your own definition of "running slow" to be able to deduce the problem and the solution.

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Quote:
Original post by CobyWalkerGames
Windows XP,OpenGL,Glut,CV++ Express

I have a simple program and its running slow.
I have a Nvidia Geforce 8800 GT.

Does OpenGL use the graphics card or just the processor?

Also I have a AMD Phenom x4 Quad core processor whats with the slow framerate?

Is OpenGL OLD/outdated? If so whats better?


[ Please don't wackily punctuate your topic lines. --Sneftel ]


There is no way to know what is wrong without knowing what you are trying to do, and we need code to look at. For all I know you are trying to do immediate mode and render 10 million polygons.

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Quote:
Original post by CobyWalkerGames
Go here:
http://www.videotutorialsrock.com/opengl_tutorial/collision_detection/video.php

Click:
"Download source code"

When Running:
Press "Space bar" 10 times


Runs fine here, GeForce 8400GS + ArchLinux, but just looking at the source code, as pointed some posts up, is using immediate mode to draw, which can be a CPU bottleneck.

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