This probably won't come as much of a surprise to most, as we have already seen a tightening of the precision requirements between Shader Model 2.0 and 3.0 as FP32 became mandatory for such parts, so it seems that Shader Model 4.0 will simply finish the job by removing the requirement of or support for partial precision.More details over here.
DirectX 10 won't have partial precision
Posted on Monday, January 30 2006 @ 20:11 CET by Thomas De Maesschalck