help with powertop

im not really sure what all this means, but this is what powertop gives me

Code:

Top causes for wakeups:
  77.6% (927.9)       <interrupt> : extra timer interrupt 
   5.1% ( 61.1)       <interrupt> : uhci_hcd:usb1, firewire_ohci, nvidia 
   4.2% ( 50.0)       S06cpuspeed : queue_delayed_work_on (delayed_work_timer_fn
   2.8% ( 34.0)       <interrupt> : uhci_hcd:usb3, ehci_hcd:usb7 
   2.2% ( 26.4)              Xorg : do_setitimer (it_real_fn) 
   1.8% ( 21.5)       <interrupt> : iwl4965, sdhci:slot0 

Suggestion: Disable the unused bluetooth interface with the following command:
  hciconfig hci0 down ; rmmod hci_usb
Bluetooth is a radio and consumes quite some power, and keeps USB busy as well.

Code:

Top causes for wakeups:
  76.4% (925.8)       <interrupt> : extra timer interrupt 
   5.0% ( 60.8)       <interrupt> : uhci_hcd:usb1, firewire_ohci, nvidia 
   4.4% ( 53.1)       <interrupt> : uhci_hcd:usb3, ehci_hcd:usb7 
   4.1% ( 50.0)       S06cpuspeed : queue_delayed_work_on (delayed_work_timer_fn
   2.3% ( 27.8)              Xorg : do_setitimer (it_real_fn) 
   1.8% ( 21.8)       <interrupt> : iwl4965, sdhci:slot0 

Suggestion: Enable the CONFIG_NO_HZ kernel configuration option.
This option is required to get any kind of longer sleep times in the CPU.

Code:

Top causes for wakeups:
  75.8% (923.4)       <interrupt> : extra timer interrupt 
   5.0% ( 61.4)       <interrupt> : uhci_hcd:usb1, firewire_ohci, nvidia 
   4.5% ( 55.1)       <interrupt> : uhci_hcd:usb3, ehci_hcd:usb7 
   4.1% ( 50.0)       S06cpuspeed : queue_delayed_work_on (delayed_work_timer_fn
   2.4% ( 28.7)              Xorg : do_setitimer (it_real_fn) 
   1.8% ( 21.8)       <interrupt> : iwl4965, sdhci:slot0 

Suggestion: enable the noatime filesystem option by executing the following comm
and:
   mount -o remount,noatime /          or by pressing the T key

i really dont know what that means, but as far as i know i have already disabled bluetooth but it keeps 'suggesting' that i disable it. Did i really disable it? or is it still running? and how can i use this app to save power? its really not changing anything if you ask me....

 

You should be using the TICKLESS feature of the kernel, available for 2.6.21 and later on x86 architecture (not supported for x86_64 yet). That is what the second comment is telling you. "Enable the CONFIG_NO_HZ kernel". Your distribution may or may not have this feature on by default. I don't know the state of Fedora these days.

The tickless feature basically allows kernel events to not be locked to a specific timer , eg. the 1000HZ timer, and so many applications and devices can sleep longer if they are not active.

The third comment is recommended to implement as well. The 'atime' is the access time of a file. So with 'atime', every time a file is read on your disk, a file write must be done to update the access time. Using 'noatime' prevents any reads from forcing a write to the disk. This usually increases disk access times and throughput, and may have an impact on power as well.

As for bluetooth... I'm just guessing here that powertop sees that you have three USB devices usb1,usb3, and usb7 and is supposing that one is bluetooth? I don't really know here.

Hope this is helpful.

 

Powertop doesn't actually save power itself; it is simply a utility to allow you to see what is draining the most power and correct it yourself. I believe the original intent was that it would be used by software and OS developers to see what kinds of thing were causing power loss so they could fix the problems through kernel and software updates/patches.

 

so will 32bit fedora be able to save more power than 64bit (im currently on 64bit)? or is it not going to be that noticable?

im hoping ubuntu will implement some good powersaving features in the october release, then i can switch.

 

The 32bit version shouldn't be noticeably different than 64bit. 64bit just has a little larger file sizes and memory footprint most times, but that shouldn't affect power usage at all.

 

Actually DYNTICKS(tickless system) is currently unavailable for 64-bit users. It is included in vanilla kernel for 32-bit systems only, for AMD64 you'll have to wait for 2.6.24. However there are available kernel patches (I think you can find them on powertop webpage) that enable dynticks for 64-bits. That's why you get so many "extra timer" wakeups