How much VRAM for textures/buffers?

Oldtimer
Posts: 834
Joined: 2002.09
Post: #1
Am I correct assuming that the amount of texture memory available resident on the video board is the VRAM size minus the memory required for video buffers, right?

A GF2MX32MB would probably have about 28 MB left for textures, under a 800x600 double-buffered color-only context, or am I way too optimistic? Smile
Quote this message in a reply
Member
Posts: 72
Joined: 2006.10
Post: #2
Quote:Originally posted by Fenris
Am I correct assuming that the amount of texture memory available resident on the video board is the VRAM size minus the memory required for video buffers, right?

The answer would be yes and no.
The short answer is yes. The openGL info window in the openGL driver monitor will confirm that (actually it claims that you have even more texture memory than that, I get about 30 Megs of texture memory on a 1024x768 display) with a 32 Mb card.

The problem is, textures are not the only things that can get cached in the "texture" memory. Some OpenGL implementations (IIRC the Red book) can cache display lists directly on the video card for example. The same thing goes for offscreen buffers, depth buffers stencil buffers etc. I don't really know wich of those get cached on the video card (i'm pretty sure that it's implementation specific though). Also, there are NVidia extensions to write memory directly in that space (to stock vertex arrays for example). So while you do have all that memory available for textures, it could get clogged up by other stuff too.

hope it helps

- Sohta
Quote this message in a reply
Oldtimer
Posts: 834
Joined: 2002.09
Post: #3
Exactly what I wanted to hear. Smile Thanks!
Quote this message in a reply
Post Reply 

Possibly Related Threads...
Thread: Author Replies: Views: Last Post
  Dynamically swapping between RAM and VRAM Shunter 7 3,836 May 22, 2009 11:44 AM
Last Post: backslash
  hmm, vram problems!! m3the01 8 3,789 Feb 12, 2008 04:18 PM
Last Post: m3the01
  Frame buffers, vertex programs and more. 8600m GT m3the01 18 7,840 Nov 18, 2007 07:34 PM
Last Post: m3the01
  Stencil buffers in an FBO... trouble TomorrowPlusX 17 7,563 Mar 23, 2006 08:19 PM
Last Post: kberg
  Pixel Buffers, Cocoa, and Mipmaps bensta00 10 5,609 Jan 24, 2005 02:11 PM
Last Post: arekkusu