tex2D<> don't support tex2D<float3>?

Accelerated Computing CUDA CUDA Programming and Performance
1

tex2D<> don’t support tex2D<float3>?
tex2D<> support tex2D<float2> and tex2D<float4>
why?

2

only 1-, 2-, and 4-component textures are supported by the hardware. I don’t know the “reason” for that, but CUDA expresses a similar hardware limitation in terms of what data sizes can be loaded by a single thread in a single instruction.