OK, I have put in /Extra a SSDT.aml for i5 from the multishit tool.
=> now : auto underclocking and Turbo Boost are working with my core i5, thanks to you !
But sleep is still broken. (My screen become white, the computer is still on)
Maybe it's impossible to activate sleep with my config, because my graphics card is not fully supported ? (Radeon HD 7850. I use GraphicsEnabler=No with Chimera)
What can I do now ?