PowerTOP 1.9    (C) 2007 Intel Corporation 

Collecting data for 15 seconds 
< Detailed C-state information is not available.>
P-states (frequencies)
Wakeups-from-idle per second : 154.1	interval: 15.0s
Power usage (ACPI estimate): 21.6W (2.2 hours) 
Top causes for wakeups:
  45.5% ( 72.3)       <interrupt> : extra timer interrupt 
  39.2% ( 62.3)      <kernel IPI> : Rescheduling interrupts 
   9.4% ( 14.9)             sleep : do_nanosleep (hrtimer_wakeup) 
   5.1% (  8.1)   <kernel module> : usb_hcd_poll_rh_status (rh_timer_func) 
   0.2% (  0.3)     <kernel core> : neigh_table_init_no_netlink (neigh_periodic_timer) 
   0.1% (  0.2)     <kernel core> : page_writeback_init (wb_timer_fn) 
   0.1% (  0.1)       <interrupt> : ahci 
   0.1% (  0.1)           kcryptd : blk_plug_device (blk_unplug_timeout) 
   0.1% (  0.1)   <kernel module> : sta_info_start (sta_info_cleanup) 
   0.0% (  0.1)       <interrupt> : PS/2 keyboard/mouse/touchpad 
   0.0% (  0.1)      <kernel IPI> : function call interrupts 
   0.0% (  0.1)           pdflush : do_journal_end (delayed_work_timer_fn) 

Suggestion: increase the VM dirty writeback time from 5.00 to 15 seconds with:
  echo 1500 > /proc/sys/vm/dirty_writeback_centisecs 
This wakes the disk up less frequenty for background VM activity

Disable Ethernet Wake-On-Lan with the following command:
  ethtool -s eth0 wol d 
Wake-on-Lan keeps the phy active, this costs power.

Suggestion: Enable SATA ALPM link power management via: 
  echo min_power > /sys/class/scsi_host/host0/link_power_management_policy
or press the S key.

Suggestion: Enable laptop-mode by executing the following command:
   echo 5 > /proc/sys/vm/laptop_mode