View Full Version : Why use OpenGL with g400?

11th February 2000, 07:04
It doesn't make ane sense to use OpenGL in games such as UT when g400 is 1.8 times faster with d3d! Only in Halflife where the d3d part is buggy(matrox falt?) it makes any sense. In Quake 1,2&3 there isn't any choice though.

Why is OpenGL that much slower?
Why is TurboGL not faster(on my machine)?

I have:
bp6 with dual celeron 466@560
128 Mb RAM
win98 second edition

11th February 2000, 07:23
You need to first remember a couple of things about the APIs (OGL and D3D).

OpenGL is Open, meaning it works on more operating systems than just Windows. D3D is Windows only. For people who don't use Windows, D3D is not an option.

OpenGL was not written for games. It's original (and still true #1 use) is professional apps. Most machines who run those type of app run "real" ($1000+) OpenGL video cards.

D3D was written primarily for games. It is generally faster because it does not do as much as OGL.

With games....it's just a matter of knowing what the game was written for.
Quake (1,2,3) was written for OGL. No choice there.

HalfLife is based largly on the Quake engine. It's still an OGL game at heart. The D3D of this game is a built-in OGL-D3D wrapper (not "real" d3d). Any time you go through a wrapper (think of it as a translator from one API to the other), it slows things down. With the Gx00, the full ICD, and/or the TurboGL, this game is best in OGL.

Unreal/UT was written for Glide (3DFX's proprietary API). D3D was added later, and OGL after that. When you select OGL in this game, you are warned that it is an "experimental implimentation". Basically, OGL with the Unreal engine blows. Since we don't have Glide on our Matrox's, D3D is the choice here.

So you see, each game is different. The majority of today's games are made for D3D. Of those that do support OGL, maybe 1/2 of them work right. Basically, if it's based on the Quake engine, use OGL. If it's based on any other engine, use D3D.

As to TGL performance on your system...that depends on a lot of things.
What drivers are you using? The 5.50 drivers are now on par with TurboGL for speed. Many people have stopped using TGL.
What res are you running at? TGL is optimized for lower resoltions (1024 and lower). Higher resolutions are the same or faster with the full ICD.

[This message has been edited by Kruzin (edited 11 February 2000).]