Might be that it is already GeForce 6
There is an article on how Valve integrated HDR into HL2 on what obstacles they need to get out of the way.
In that article they mention that one of the GeForce generations (not sure if it was GF5 or 6 now that I think more about it) needed to use 16Bit as 32bit was not fully hardware supported. In the end thought it would make sense if the GF6 were capable of it, as NVidia Tech is always a generation in front compared to ATI
At simplest you create a little test app that you offer to people to see where it works full hardware accelerated and where through fakes / lower precision that especially generates profiling data. So you know which generations actually were capable of doing it at a usefull performance. Because support only is not of much use unless you plan to write a still renderer ;-)
There is an article on how Valve integrated HDR into HL2 on what obstacles they need to get out of the way.
In that article they mention that one of the GeForce generations (not sure if it was GF5 or 6 now that I think more about it) needed to use 16Bit as 32bit was not fully hardware supported. In the end thought it would make sense if the GF6 were capable of it, as NVidia Tech is always a generation in front compared to ATI
At simplest you create a little test app that you offer to people to see where it works full hardware accelerated and where through fakes / lower precision that especially generates profiling data. So you know which generations actually were capable of doing it at a usefull performance. Because support only is not of much use unless you plan to write a still renderer ;-)