Some new information about ATi's new R420 graphics core. According to The Inquirer it will use something ATI calls 3Dc, a new way of compression which ATI will supply as an open standard.
3Dc will be able to perform similar level of quality as normal non compressed textures, we learn, but it wont be able to compress all data. It might lose information about light and shadow stuff.
It will certainly speed things up r and R300 marchitecture tweaked up to R420 runs things faster then without. ATI is claiming 8.8 to 1 compression for R300 if I remember correctly and it was always rather good with these optimisations. However, I'd urge caution about these claims, as the R300 could compress data in 8.8 to 1 ratio only if you were talking about a black screen with information about only the black shade.
Source: The Inquirer