I've got a .dds texture that I downloaded and made changes to ( I will contact the author and ask them when ready ), but there is something amiss. My guess was that their texture is DX1, because it has no Alpha channel. So I save in DX1 as well, with Generate MipMaps checked.

My file:

2048 x 2048 - 2,731 KB

Their file

2048 x 2048 - 16,385 KB

Why is my file smaller? When I look at their file, the mode is at 8 Bit just like mine. Same resolution just like mine. That is a huge slimdown for a few simple changes to a skin texture. I tried saving in DX3 and DX5 and got up to 5,xxx KB, still much smaller.

Perhaps it was saved with no compression at all. I don't know if that's even possible with .dds.