( ricsip | 2021. 05. 06., cs – 13:17 )

Global C states -t keresd az Advanced \ AMD CBS menü alatt:

Here's AMD talking C-States setting in BIOS https://youtu.be/NRSUYBjlBXw?t=5085

They should be enabled by default. But sometimes mobos have them on 'auto' which actually means disabled, and sometimes they just completely forget to enable.


Nézd meg Linux alatt hogy jelenleg milyen C állapotok vannak engedélyezve (valami majd megírja milyen tool tudja ezeket kilistázni)


Global C-state might be disabled by default for better stability when resuming from standby.

I also sort of oversimplified the C-states thing as just relating to standby. The C1 state is just the idle state - operating systems have traditionally sent a 'HLT' instruction to the processor any time it runs out of work to do - the idle % would essentially be how often the CPU was 'executing' the 'HLT' instruction (this execution would occur on the fetch circuitry while the main execution units of the core were idled). There was an enhanced version of this that also reduced voltage at the same time.

C2 is something of a 'deep idle" or 'light sleep' state where hardware was used to cut the clock signal instead of software - this is the 'Standby' from the Windows 95/98 era.

C3 is a more proper sleep mode where the CPU is almost completely off and external hardware (chipset) would need to wake the system back up - usually by pressing the power button or some other interrupter. How far C3 goes depends on the hardware - with some systems turning off nearly everything.

C4, C5, C6 are deeper sleep states that are basically ever lower amounts of voltage and active circuits.

What "Global" means in this context isn't entirely clear to me, but it could mean shutting down the entire CPU during standby/sleep.