For low-end computers, you can perform your post-processing using the 8-bit channel textures... It will look a bit worse, but again will use half the bandwidth.

That mean, if I correctly understand, ToneMap is the first post process of the chain.

DXGI_FORMAT_BC1_UNORM_SRGB

Four-component block-compression format for sRGB data. For information about block-compression formats, see Texture Block Compression in Direct3D 11.

I don't understand why there is a texture state like that, I don't have looked in openGL spec, but I guess it has a similar one.

I don't understand why there is a texture state like that, I don't have looked in openGL spec, but I guess it has a similar one.

It's not a "texture state", it's a compressed texture format. When you use it, you're saying "the data in this texture should be interpreted as if it contains colors in the sRGB color space", which effectively causes the hardware to apply sRGB->Linear conversion when you sample from the texture.

It was a "sampler state" pre- DX10

gamma correction and tonemapping are 2 separate context. sRGB is related to gamma correction by the simple fact that sRGB assume a particular gamma value. Gamma correction is related to being able to reproduce accurate color across different display device, while tonemapping is concern with mapping color values ( luminance ) into a range that can be displayed on a display device giving the device limitation. One can do gamma correction with no concern for tonemapping if the values they are manipulating lies within the range on displayable values for the output device, and vice versa.

gamma correction and tonemapping are 2 separate context. sRGB is related to gamma correction by the simple fact that sRGB assume a particular gamma value. Gamma correction is related to being able to reproduce accurate color across different display device, while tonemapping is concern with mapping color values ( luminance ) into a range that can be displayed on a display device giving the device limitation. One can do gamma correction with no concern for tonemapping if the values they are manipulating lies within the range on displayable values for the output device, and vice versa.

But technically Gamma decoding is tonemapping as well.