What Gets Loaded in Video RAM?

Started by
6 comments, last by a2k 24 years ago
supposing i want to load textures, but if i have 8 mb of vram, and then load up 8mb of textures, is the video ram used for anything else besides loading textures? i.e. is there a rule that i should leave so much for other things? a2k Edited by - a2k on 4/13/00 9:25:25 PM
------------------General Equation, this is Private Function reporting for duty, sir!a2k
Advertisement
Well, if you 8mb of vram, and load 8mb of textures into vram:
8 - 8 = 0 free mbs

So no, vram would be full, and you couldn''t do anything else.

if you have no vram left, you can use system memory, but it will be slightly slower since it has to go throught the PCi BUS or something. Theres no defined "rule" for how much vram you should leave open, just decide how important the texture''s speed is to your game.
Zipster, I think a2k was wondering if there is something that vram is used for that he couldn''t control or something he''ll be forced to use it for.
Like the fact that 128 mb of sysram does not allow you to load up 128 mb of textures, at least not without using virtual memory.
But I don''t know anything about it, though
A polar bear is a rectangular bear after a coordinate transform.
well, i was just actually wondering if i''m free to just load as much of my textures will fit into vram, or should i allow some of like, some opengl functions or something into vram somehow, yeah, like armitage was saying....

a2k
------------------General Equation, this is Private Function reporting for duty, sir!a2k
well some of that 8mb would be used by the card its self for things like video buffer... but I would recomend leaving a little... you never know what the card is going to pulll on ya... like maby it just allocates some vram when it needs it to do maby something like alpha tranc or something wierd like that... I don''t think it should but I''d leave some left over

Great Milenko

Words Of Wisdom:
"Never Stick A Pretzel In Your Butt It Might Break Off In There."


http://www.crosswinds.net/~milenko
http://www.crosswinds.net/~pirotech

The Great Milenko"Don't stick a pretzel up your ass, it might get stuck in there.""Computer Programming is findding the right wrench to hammer in the correct screw."
when a bitmap is loaded into memory, it IS loaded into video ram, right?

a2k
------------------General Equation, this is Private Function reporting for duty, sir!a2k
That depends a2k.
If you just load the bitmap, then no, it is not stored in video memory.

If you use OpenGL to create a texture from that bitmap, then the texture is put into video RAM.
If you go over your allowed amount of VRAM, OpenGL will start to use system memory for storing textures.
This is when you fall off a performance cliff.
You can alter the way GL stores textures with glPrioritizeTextures(), it helps but it isn''t perfect.

Note I assume you are using GL since you mentioned it in an earlier post. also note I could be wrong, but I think the info is correct.

Take it easy,

-Mezz
actually, if you use DirectX, you load a bitmap onto a surface, and the surface is either in vram or system memory.

This topic is closed to new replies.

Advertisement