A height on a height map is only 8 bit. Use a (256 colour) grey scale image.
16 bit colour image has less bits on the red channel.
3 x 8 bit images uses the same memory as 1 24 bit image. So if you use grey scale images for your land types etc too then you'll be fine without the need to worry 32 bit speed problems.
16 bit colour image has less bits on the red channel.
3 x 8 bit images uses the same memory as 1 24 bit image. So if you use grey scale images for your land types etc too then you'll be fine without the need to worry 32 bit speed problems.