Originally Posted by jlippo
Indeed, normal PC could have problems with disk trashing.
We do know there is at least 2 128kx128k megatextures in the game.
When uncompressed textures would hold something like with 4bytes for RGB + specular strenght then 2 or 3 bytes for normalmapping and 1 or 2 bytes for something else.
That is 2*RGBA textures or 8bytes per texel.
Single 128k texture uncompressed with 8 bytes/texel is ((128000*128000)*8)/1000000000~131,072GB.
With DXT1 compression the size would be around 30-40GB depending on what channels they use and for what. (and thus what DXT method is used.)
Id Tech uses something similar to JPEG but most likely in YCoCg color space.
We might get some kind of 'less' compressed version which takes huge amounts af disk space, but uncompressed no way.
Also on PC it might be possible to not re-compress the data to DXT before viewing so there might be one of the quality improvements over console versions.
Theres an article in a pdf that JC did about his new compression, seems like I found it over at B3D... Anyway, his compression routine is 10 to 1 or 20 to 1 depending on the quality you want.