Reducing HP 4720s power consumption under Ubuntu Linux 11.10

#!/bin/sh -e
# Increase filesystem write cache timeoutecho 1500 > /proc/sys/vm/dirty_writeback_centisecs
# Enable power management on all PCI devices
find /sys/devices/pci* -path "*power/control" -exec bash -c "echo auto > '{}'" \;
# Enable power aware CPU scheduler 
echo 1 > /sys/devices/system/cpu/sched_mc_power_savings
# Enable WLAN power management 
iwconfig wlan0 power on
# Enable Intel audio power management 
echo 1 > /sys/module/snd_hda_intel/parameters/power_save
# Enable SATA power management 
for i in /sys/class/scsi_host/host*/link_power_management_policy; do echo min_power > $i; done 
# Enable laptop mode tools 
echo 5 > /proc/sys/vm/laptop_mode
# Override PCIE power management
echo powersave > /sys/module/pcie_aspm/parameters/policy
# Disable wake on lan for LAN
ethtool -s eth1 wol d

pcie_aspm=force

GRUB_CMDLINE_LINUX="pcie_aspm=force"

        Option      "NoDRI"
        Option       "no_dri" "no"