From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751171AbcBLIuh (ORCPT ); Fri, 12 Feb 2016 03:50:37 -0500 Received: from mail-lf0-f54.google.com ([209.85.215.54]:35241 "EHLO mail-lf0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750995AbcBLIuf (ORCPT ); Fri, 12 Feb 2016 03:50:35 -0500 From: moosotc@gmail.com To: linux-kernel@vger.kernel.org Subject: Energy consumption oddity on a Mac-Mini Date: Fri, 12 Feb 2016 11:50:32 +0300 Message-ID: <87k2mauxbb.fsf@gmail.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.0.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Trying to make Linux consume as little(or less) power as OS X does on this Mac mini (as measured by watt meter that sits between the box and the power outlet) led me to the following sequence of commands: [..start script..] #!/bin/sh set -e test "$(id -u)" != "0" && exec sudo "$0" "$@" echo powersave >/sys/module/pcie_aspm/parameters/policy echo 1 >/sys/module/snd_hda_intel/parameters/power_save echo min_power >/sys/class/scsi_host/host0/link_power_management_policy echo 1 | tee >/dev/null /sys/bus/usb/devices/*/power/autosuspend echo auto | tee >/dev/null /sys/devices/**/power/control # Suspend to RAM only to restore in six seconds # for some reason this step is essential here: # product: Macmini7,1 (System SKU#) # vendor: Apple Inc. # version: 1.0 echo +6 >/sys/class/rtc/rtc0/wakealarm echo mem >/sys/power/state echo 0 >/sys/class/rtc/rtc0/wakealarm [..end script..] Last 3 lines are the source of my confusion, why is this needed? The situation is as follows: * after boot the system consumes 8-9 watts * with powertop(8) inspired sysfs tweaks but without the suspension 6-7 * with the suspend oscillating around 5-6 Would be nice to really know what's going on here. (My Linux-power-fu is not too great) -- mailto:moosotc@gmail.com