» Tue May 15, 2012 11:06 pm
Depends on the user setting really. If someone is starting out by trying to max out the game and/or are using a custom rageconfig acquired from elsewhere, it's quite probable that they have texture compression switched off (most of these configs contain some quite dangerous options). That's why it's important when troubleshooting things to revert back to a default config with lower settings, then gradually take them up.
I more than half suspect that id may be using the alpha channel for stashing some extra info in, so that restricts the options to DXT3 or DXT5; which would be one quarter of the size of 32-bit uncompressed. Still 256 MB for 8k textures, which, when added to framebuffer memory (including probably multiple FBOs for post proc effects), vertex buffers, index buffers, and all the rest, mounts up quite heavily.