[modeless]

There are many GPUs with no double precision floating point support in hardware. Modern ones can probably emulate it. Older ones don't have any explicit support. Most real time 3D renderers do not use double precision at all.

[gbrown_]

> There are many GPUs with no double precision floating point support in hardware.

Which ones? I'm genuinely curious about this.

[modeless]

I think all of the ones listed as DirectX 10.1 or lower on this page: https://en.wikipedia.org/wiki/Feature_levels_in_Direct3D

Those are all quite old now of course, but even modern GPUs may not have 64-bit ALUs and rely on emulation instead. Intel Gen11 in Ice Lake, for example: https://01.org/sites/default/files/documentation/intel-gfx-p...

In mobile architectures 64-bit ALUs can be an optional feature that is omitted for lower end configurations. I know this is true of PowerVR.

[gbrown_]

Ah interesting to know about Gen11, thanks for the links.