System Sleep States and further very interesting sources

https://web.archive.org/web/20220518221649/https://01.org/linuxgraphics/gfx-docs/drm/admin-guide/pm/sleep-states.html

https://web.archive.org/web/20220916021828/https://01.org/linuxgraphics/gfx-docs/drm/admin-guide/pm/working-state.html

https://web.archive.org/web/20220916021829/https://01.org/linuxgraphics/gfx-docs/drm/admin-guide/pm/cpuidle.html

https://web.archive.org/web/20220916021828/https://01.org/linuxgraphics/gfx-docs/drm/admin-guide/pm/intel_idle.html

https://web.archive.org/web/20220916021828/https://01.org/linuxgraphics/gfx-docs/drm/admin-guide/pm/cpufreq.html

https://web.archive.org/web/20220916021830/https://01.org/linuxgraphics/gfx-docs/drm/admin-guide/pm/intel_pstate.html

https://web.archive.org/web/20220916021829/https://01.org/linuxgraphics/gfx-docs/drm/admin-guide/pm/intel_epb.html