Silence when in suspended mode

[Haggis McMutton]

I just installed Ubuntu and I was playing with the shutdown options. I
tried shutdown and instead of going into low power mode it appeared to
shut down the computer completely. Hard drives clicked off and the fan
stopped.

OK, I thought. Pressed power to start the computer up, I could hear the
fan and hard drives start up again, then suddenly I was looking at the
desktop. It appeared it did go into suspend mode but whilst in this noise
the computer made no noise at all.

How is this possible. Surely some CPU power is needed to keep everything
in active memory and with no cooling fans isn't this bad for the
computer's health?

 

[Haggis McMutton]

I just installed Ubuntu and I was playing with the shutdown options. I
tried shutdown

Sorry that should be 'I tried suspend'

whilst in this noise

'Whilst in this mode'

 

[David Sudlow]

I just installed Ubuntu and I was playing with the shutdown options. I
tried shutdown and instead of going into low power mode it appeared to
shut down the computer completely. Hard drives clicked off and the fan
stopped.

OK, I thought. Pressed power to start the computer up, I could hear the
fan and hard drives start up again, then suddenly I was looking at the
desktop. It appeared it did go into suspend mode but whilst in this noise
the computer made no noise at all.

How is this possible. Surely some CPU power is needed to keep everything
in active memory and with no cooling fans isn't this bad for the
computer's health?

I think the answer is that in this state so little power is being used
that ambient cooling is adequate.

 

[GT]

I think the answer is that in this state so little power is being used
that ambient cooling is adequate.

But what about power supply heat?

 

[Mike Walsh]

This sound more like hibernate than suspend.

I just installed Ubuntu and I was playing with the shutdown options. I
tried shutdown and instead of going into low power mode it appeared to
shut down the computer completely. Hard drives clicked off and the fan
stopped.

OK, I thought. Pressed power to start the computer up, I could hear the
fan and hard drives start up again, then suddenly I was looking at the
desktop. It appeared it did go into suspend mode but whilst in this noise
the computer made no noise at all.

How is this possible. Surely some CPU power is needed to keep everything
in active memory and with no cooling fans isn't this bad for the
computer's health?

 

[David Sudlow]

This sound more like hibernate than suspend.

No this is the ACPI S3 state also known as Suspend to RAM in Linux.
Hibernate is the ACPI S4 state also known as Suspend to disk. The OP is
clearly describing the former state as resuming from the latter involves
the bios boot sequence and grub before reading the hibernation file
from disk. I don't know the state of PSU fan on a desktop in the S3
state as I don't have a desktop which uses ACPI.