[RESOLVED] PC Sleep -- looking for confirmation

[Qqmike]

Have used PCs since 1981 (IBM). Built DIY Linux PCs since 2005.
Having said that, I feel good enough to ask stupid questions. Maybe looking for confirmation.

Question is: When a PC sleeps/suspends, do the fans (case & CPU) turn off?

What got me here:
Just installed K24.04.1 into a 2nd drive (M.2) on my PC. No problems.
Noticed * for the first time in my PC career * this screen (that I only ever used to turn off the display after x minutes):


System Settings > Power Mgt -> Energy Saving -> Automatically Sleep after 15 minutes, set in my K24.04 system. NOT set ever in my previous Linux systems.
(the screenshot is made in K22.04 as an example only)

I found out! Was booted into K24.04, last night after more than 15 minutes saw the power button on PC case blinking nicely, all fans off, it woke up when I moved the mouse.

Now, as I understand it, in sleep, the whole show moves to RAM, there should be nothing working (power-wise), no heat generated.
Quick search tells me this is so: guys at ASUS ROG saying the PC is basically 'off,' so fans also go off. In fact, some people complain that their fans don't go off during sleep.

Speaking of "off," in K24.04, I turned off the suspend-sleep function! I run my PCs 7x24, occasionally re-boot, almost never shutdown. No problems with PCs or my electric bill.

Do you sleep experts confirm all this?

Data:
System is a good one, recently built (Nov 2021), Prime ASUS mobo Z590-P, Corsair power supply RM750X, i5-10500 Intel CPU.

[Snowhog]

Are you asking about the behavior in K24.04.1 or K22.04? Asking as you posted in 22.04, but your question appears to be about 24.04.

[Qqmike]

Asking about sleep -- fans turn off, too? I thought I made it clear I was in 22.04 posting about 24.04.
But ... it shouldn't matter. The issue is the safety of "sleep" w/fans off.

[Qqmike]

Thinking why does the OS matter?
Just one thing here, but not too relevant: Only in K24.04 have I ever seen Suspend -> Sleep set automatically on a fresh install. At first, I thought the power (to the house) went off (flickered). Then wondered if my PS was failing!

[Snowhog]

On my desktop PC, the fans are powered off when it enters Sleep. I've experienced no ill effects.

[Qqmike]

Thanks, Snowhog. It actually makes sense. I think I was startled b/c I didn't expect anything sleeping (not even myself, let alone the PC).
As a DIY builder, it's usually really bad to see your fans not moving!

[Virginio Miranda]

Have used PCs since 1981 (IBM). Built DIY Linux PCs since 2005.

Question is: When a PC sleeps/suspends, do the fans (case & CPU) turn off?

I run my PCs 7x24 too. Never shutdown.

i can corfirm when a PC sleeps/suspends, do the fans (case & CPU) turn off. All of them.

[Qqmike]

Thanks for your feedback, Virginio.