Messages in this thread | | | Date | Thu, 20 Jan 2000 09:26:14 -0800 (PST) | From | Andy Henroid <> | Subject | Re: 2.3.40-5 -- "apm" no longer recognizes that I have an APM-ena bled kernel. |
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--- Jamie Lokier <lkd@tantalophile.demon.co.uk> wrote:
> The only visible effect is that the laptop won't > suspend any more. > Something obviously got set because when acpid is > killed, the laptop > still doesn't suspend.
Right, APM is not being engaged when it is overriden by ACPI so I wouldn't expect APM suspend to work at all. Further, once acpid is started, ACPI is enabled in the BIOS. After that any attempt to use APM features is going to fail (yes, even after acpid is killed).
> My question is: is there any advantage for me in > enabling ACPI in the kernel, and/or running acpid > at the moment? Will the laptop consume less power > than when it's using APM?
Depends on how good of an APM/ACPI implementation you have. ACPI C-states definitely save power and most ACPI laptops support at least C1 and C2 (C3 is the deepest processor power state). Some APM implementations allow the CPU to be slowed.
I don't know what the actual power savings of C-states vs. APM CPU slowing are on your system. It might be interesting to test it out and see which causes your battery to last longer.
-Andy
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