Fractional Bit Precision in R420

[Luminescent]

Does anyone know how many bits of fractional precision R420 offers for texture filtering ops, etc.? I remember there being some commotion about the limited 5-bit precision available in R3xx and was wondering whether or not this was increased for R420.

 

[KimB]

That's a damned fine question, but I expect the answer is no. There are so few changes between the R3xx and R4xx that I doubt they would have changed this.

 

[Luminescent]

I know OpenGl guy mentioned that the alpha blending calculation (which sports a 1 lsb difference from refrast) remained the same (or similar) for R420, which makes me wonder about the fractional precision for tex ops.

 

[Xmas]

It's the same. 6 bits for bilinear filtering, 5 for mipmap blending, IIRC.