[ltp] X61s power consumption

Tino Keitel linux-thinkpad@linux-thinkpad.org
Wed, 25 Jun 2008 20:41:48 +0200

On Fri, May 23, 2008 at 12:14:36 -0400, Theodore Tso wrote:
> On Fri, May 23, 2008 at 05:34:01PM +0200, Tino Keitel wrote:
> > 
> > what power consumption can I expect from a X61s, 1,6 GHz (L7500) and 2
> > GB RAM in a minimal environment (no USB driver loaded, WLAN disabled,
> > lowest display brightness, hard disk spun down etc.)?
> 8-9 Watts.  See:

For the records:

I measured slightly below 9 Watts (the lowest was 8,7 Watts) with and
idle Xfce desktop, active wireless (but only light traffic) and these
power saving features turned on:

1. wireless power saving:

echo 5 > /sys/bus/pci/drivers/iwl4965/*/power_level

2. dark display (not very usable, though)

xbacklight -set 0

3. ethernet power saving

ip link set eth0 down
ethtool -s eth0 wol d
ethtool -s eth0 speed 100

4. disabled CardBus

cd /sys/bus/pci/drivers/yenta_cardbus
for i in 0* ; do
        echo -n "$i" > unbind

rmmod yenta_socket

5. no USB

rmmod uhci_hcd
rmmod ehci_hcd

6. low display refresh rate

xrandr --rate 40

7. hard disk power saving (spin down when idle)

- mounted all ext3 partitions with commit=20000,reltime mount options
- used a patched noflushd that works with libata

8. no sucky applications

- kill apps like gkrellm, firefox etc. that constantly eat CPU power

9. SATA link power management

echo min_power > /sys/class/scsi_host/host0/link_power_management_policy

10. Intel Speedstep for both cores

cpufreq-set -g ondemand
cpufreq-set -g ondemand -c1

Is there anything that I missed (except for ugly hacks like