This achieves about 20-30 watts. Here's the cpuinfo:

cat /proc/cpuinfo 
processor   : 0
vendor_id   : GenuineIntel
cpu family  : 6
model       : 14
model name  : Genuine Intel(R) CPU           T2500  @ 2.00GHz
stepping    : 8
cpu MHz     : 1000.000
cache size  : 2048 KB
physical id : 0
siblings    : 2
core id     : 0
cpu cores   : 2
fdiv_bug    : no
hlt_bug     : no
f00f_bug    : no
coma_bug    : no
fpu     : yes
fpu_exception   : yes
cpuid level : 10
wp      : yes
flags       : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx constant_tsc pni monitor vmx est tm2 xtpr
bogomips    : 3999.16
clflush size    : 64

processor   : 1
vendor_id   : GenuineIntel
cpu family  : 6
model       : 14
model name  : Genuine Intel(R) CPU           T2500  @ 2.00GHz
stepping    : 8
cpu MHz     : 1000.000
cache size  : 2048 KB
physical id : 0
siblings    : 2
core id     : 1
cpu cores   : 2
fdiv_bug    : no
hlt_bug     : no
f00f_bug    : no
coma_bug    : no
fpu     : yes
fpu_exception   : yes
cpuid level : 10
wp      : yes
flags       : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx constant_tsc pni monitor vmx est tm2 xtpr
bogomips    : 3994.72
clflush size    : 64

Powertop

Cn                Avg residency       P-states (frequencies)
C0 (cpu running)        ( 7.5%)         2.00 Ghz     0.0%
polling           0.0ms ( 0.0%)         1.84 Ghz     0.0%
C1                0.0ms ( 0.0%)         1.67 Ghz     0.0%
C2                0.0ms ( 0.0%)         1000 Mhz   100.0%
C4                6.0ms (92.5%)

Wakeups-from-idle per second : 154.0    interval: 15.0s
no ACPI power usage estimate available

Top causes for wakeups:
  25.6% ( 57.7)   USB device  1-2 : Apple Internal Keyboard / Trackpad (Apple Computer) 
  22.8% ( 51.3)        : uhci_hcd:usb1, ehci_hcd:usb5 
  15.6% ( 35.1)        : extra timer interrupt 
  11.3% ( 25.5)       : Rescheduling interrupts 
   7.3% ( 16.5)        : acpi 
   6.1% ( 13.7)        : wifi0 
   2.2% (  5.0)            pommed : sys_timerfd_settime (timerfd_tmrproc)
   1.8% (  4.0)    : usb_hcd_poll_rh_status (rh_timer_func)
   1.3% (  2.9)    wpa_supplicant : scan_restart (scan_next)
   1.1% (  2.5)       firefox-bin : futex_wait (hrtimer_wakeup)
   0.9% (  2.1)              Xorg : schedule_timeout (process_timeout)
   0.9% (  1.9)      : input_handle_event (input_repeat_key)
   0.5% (  1.1)        : uhci_hcd:usb2, firewire_ohci, ata_piix
   0.4% (  1.0)           openbox : schedule_timeout (process_timeout)
   0.4% (  0.9)      : queue_delayed_work_on (delayed_work_timer_fn)
   0.3% (  0.6)   gnome-screensav : schedule_timeout (process_timeout)
   0.2% (  0.5)       gnome-panel : schedule_timeout (process_timeout)
   0.1% (  0.3)   gnome-power-man : schedule_timeout (process_timeout)
   0.1% (  0.3)              Xorg : do_setitimer (it_real_fn)
   0.1% (  0.3)      : uhci_scan_schedule (uhci_fsbr_timeout)
   0.1% (  0.3)          nautilus : schedule_timeout (process_timeout)
   0.1% (  0.3)              hald : schedule_timeout (process_timeout)
   0.1% (  0.2)              init : schedule_timeout (process_timeout)
   0.1% (  0.2)    wpa_supplicant : __netdev_watchdog_up (dev_watchdog)
   0.1% (  0.2)    mapping-daemon : schedule_timeout (process_timeout)
   0.1% (  0.2)      : neigh_table_init_no_netlink (neigh_periodic_timer)
   0.1% (  0.1)               gdm : start_this_handle (commit_timeout)
   0.0% (  0.1)         dhclient3 : schedule_timeout (process_timeout)
   0.0% (  0.1)              cron : do_nanosleep (hrtimer_wakeup)
   0.0% (  0.1)             touch : start_this_handle (commit_timeout)
   0.0% (  0.1)      : ip_rt_init (delayed_work_timer_fn)
   0.0% (  0.1)       firefox-bin : uhci_scan_schedule (uhci_fsbr_timeout)
   0.0% (  0.1)      : neigh_add_timer (neigh_timer_handler)

A USB device is active 100.0% of the time:
USB device  1-2 : Apple Internal Keyboard / Trackpad (Apple Computer)

Heat

By far the biggest problem I've had with my Macbook has been its heat. I finally tracked down a solution! By setting laptop mode to on while power is supplied by AC, the temperature of the device drops significantly. This is great!

'''/etc/laptop-mode/laptop-mode.conf '''

ENABLE_LAPTOP_MODE_ON_AC=1

External Links

  • http://wiki.debian.org/MacBook
  • http://dentifrice.poivron.org/laptops/macbook/