On Sat, Nov 29, 2014 at 5:07 PM, Marcus MERIGHI <mcmer-open...@tor.at> wrote: > n...@holland-consulting.net (Nick Holland), 2014.10.25 (Sat) 06:08 (CEST): > > [big snip of the original discussion on screen blanking and it's > handling by mplayer] > >> Personally, I'm slowly losing interest in screen blanking. LCD screens >> draw little power when on, [...] > > [snipping again] > >> A laptop plugged into the wall...why power down the screen at all? A >> laptop running on batteries...if you aren't going to use it, why not >> just suspend it? > > When I read this I thought that there was some room between "not using" > and "justifies suspend". (It only took two months until I got going...) > > For quick power saving, stand-by would do. It takes 2 seconds to go to > stand-by, 7 seconds to resume (dmesg below). > > This is fast enough for intentional breaks, I think. > > But with me sitting in front of the machine, what happens by far more > often are unintentional breaks, i.e. me staring and thinking (or not), > or me trying to get work done but being interrupted, leaving the machine > in a hurry. > > Time driven automagic (xidle(1)) stand-by would be too much for these > cases, there may be tasks running that I want to continue. > > But screen blanking/unpowering? This cannot hurt, but does it help > to save power? (Not only for working longer but also for the > environment...) > > All numbers taken on a lenovo X200s (dmesg follows) with batteries > removed, a cheapish power meter and only default deamons running (and > doing nothing). What might matter and isn't easy to see/not visible in > the dmesg, my sd0 (MKNSSDCR120GB) is an SSD with atactl(8) smartenable, > writecacheenable, acousticset 126, apmset 126. > > 1.1 W stand-by - apm -S > 12.5 W display off - xrandr --output LVDS1 --off > 15 W display 10% - xbacklight -set 10 > 20 W display 100% - xbacklight -set 100 > > So in the range between 1.1 W (minimum idle power consumption) and 20 W > (maximum idle power consumption), turning the screen off automagically > saves me eight Watts out of 19 that could be saved (if I had left > intentionally and used stand-by). Almost half of the maximum power > saving achieved by unpowering the screen if leaving in a hurry is good > enough for me.
When on battery, I set brightness to 40% using "wsconsctl display.brightness=40" and lock the screen using "xlock -dpmsoff 1" when I'm afk... > Bye, Marcus Ciao! David
