32 bit z-buffering

[TRDLE]

I had an upgrade to my computer a few months ago with a G400 card. I noticed that the "use 32bit z-buffering" option was not checked. Should it be? Does it impact performance by much? My system specs are:
AMD 350 mhz k6-2
128 mg ram
Acorp-5ali61 main board

Yes I know I should have a faster cpu, I'm thinking of changing to a faster processer that will work with this mainboard, perhaps a K6-2, or K6-3 450-550 mhz. Thanks for any comments and suggestions.

[impact]

From my personal experience, turning z-buffering off halves the performance of NFS:HS. So you definitely want to have it on.

The z-buffering does the 3D 'depth control' that determines which parts of scene to render and which not. With z-buffering off, the whole scene is rendered, with z-buffering on, only the visible parts are rendered, which is much faster and also looks more realistic.

[waxling]

K, impact I think you missed the question..

He asked should he use "32 bit z-buffering"?
From my understanding 32 bit z-buffering affects the accuracy of z-buffer calculations...

What that means I'm not really sure, but it makes it look better for a minor performance hit.

[impact]

Oh you mean like vs 16 bit z-buffer or something... well I am not sure. 32 would give you higher precision probably.

[Alec]

One thing´s for sure, a 32-bit Z-buffer eats up more video memory than the a 16-bit one. It probably comes with a small performance hit. However, a 32-bit Z-buffer does the z-axis calculations more accurately, eliminating possible errors in the rendering and enabling a more in-depth view of the whole 3D scene.

[This message has been edited by Alec (edited 13 March 2000).]

[Nuno]

32 bit z-buffer only makes a difference if the game was coded with that in mind. If the game was made expecting a 16-bit z-buffer, you don´t gain nothing in visual quality enabling 32-bit z-buffer, because 16 bit acuraccy calculation do the same. But if 32 bit z-buffer is enabled, you get a performance hit due to higher memory bandwidth requirements.
If the game was coded with a 32 bit z-buffer in mind - *hint* Quake3 *hint* then 32 bit z makes a diference and you´ll have artifacts if using only 16 bit z-buffer.
So basically use 16 bit z-buffer for everything except Q3 (and maybe UT, don´t know for sure)

[wenDigo]

and also FreeSpace2...