Talk:N900 Hardware Power Consumption

(added more reasoning and a few general guidelines about how wiki works)
m (Reverted edits by 212.52.28.66 (Talk) to last revision by l29ah)
 
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Moved the whole thing to discussion since that's where it belongs when it turns into a talk
Moved the whole thing to discussion since that's where it belongs when it turns into a talk
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  those values are moot - for the first 2 it's irrelevant which process is *idle* since the CPU should zeroclock anyway, alas here it's at fixed clock-freq which is NOT recommended. For the rest the only useful audio source to run those tests is a pink noise at 0dB. See `man sox` for how to create such file. Or to set volume to 1 step above zero, see above - so the whole music content becomes irrelevant. For arbitrary music the amplifier will introduce random "noise" up to 2000mW to the figures. The BQ24150 can't average out that noise. Further there's "GUI on" which means "backlight" and that's very random and even depending on ambient light, see 3 bullets above --[[User:joerg_rw|joerg_rw]] 12:52, 13 May 2015 (UTC)
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  those values are moot - for the first 2 it's irrelevant which process is *idle* since the CPU should zeroclock anyway, alas here it's at fixed clock-freq which is NOT recommended. For the rest the only useful audio source to run those tests is a pink noise at 0dB. See `man sox` for how to create such file. Or to set volume to 1 step above zero, see above - so the whole music content becomes irrelevant. For arbitrary music the amplifier will introduce random "noise" up to 2000mW to the figures. The BQ27200 can't average out that noise. Further there's "GUI on" which means "backlight" and that's very random and even depending on ambient light, see 3 bullets above --[[User:joerg_rw|joerg_rw]] 12:52, 13 May 2015 (UTC)
  Not fixed, it's ondemand w/ bottom freqs allowed as specified.
  Not fixed, it's ondemand w/ bottom freqs allowed as specified.
  I restarted the same track every time, so the comparison should be quite  adequate, tho a noise would be better, yep. Also, where did you get the information regarding the bq24150 performance? Such spikes (if there are any) would be smoothed by the capacitors on the power lanes and then detected by bq24150, no? I didn't get any numbers on it from the datasheets tho.
  I restarted the same track every time, so the comparison should be quite  adequate, tho a noise would be better, yep. Also, where did you get the information regarding the bq24150 performance? Such spikes (if there are any) would be smoothed by the capacitors on the power lanes and then detected by bq24150, no? I didn't get any numbers on it from the datasheets tho.
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When there's GUI ON then what's the meaning of that when there's no backlight?
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When there's GUI ON then what's the meaning of that when there's no backlight?
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Generally those values over at main page are meant to be reproducable by others, otherwise they are useless. Neither a "GUI ON, BackLight Off" nor "always same (unknown) random music file" is reproducable by others.
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Huh? It's a client-server app. [[User:l29ah|l29ah]] 00:01, 16 May 2015 (UTC)
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Generally those values over at main page are meant to be reproducable by others, otherwise they are useless. Neither a "GUI ON, BackLight Off" nor "always same (unknown) random music file" is reproducable by others.
 +
 
 +
The numbers just compare the battery-friendliness of different music players. You can retest it properly and get the same differences. [[User:l29ah|l29ah]] 00:01, 16 May 2015 (UTC)
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And honestly when you state "A yields wrong numbers, B yields correct numbers" and somebody is challenging this statement,
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  "CITATION NEEDED! Why should a shell script and i2cget be inferior to a perl script and a deprecated kernel module? --joerg_rw 12:18, 13 May 2015 (UTC)
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then an answer like
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  Go measure it yourself. l29ah 23:40, 14 May 2015 (UTC)"
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is neither sufficient nor convincing nor appropriate for a wiki. What makes you think *your* script is the one that has the better more accurate values?
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I compared their output at rest and in polling mode and observed the shell script consumed noticeably more power. I doubt we're talking about the same one tho: the one i've poked was called bq27k-detail2. You can retest it yourself; i don't care much of publishing it paranoida^Waccurately, just wanted to share my results that i find quite helpful regardless the flaws you're talking about. [[User:l29ah|l29ah]] 00:01, 16 May 2015 (UTC)
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You obviously don't even completely understand the operation modes of the bq24150 OOPS sorry bq27200 chip. Hint: load your "always same mp3 file" into audacy, mark a 2.56s window at a random point of time and calculate the total energy in that window. Then move the window and see how the total energy changes depending on the segment of the song you look at. And why would any user be interested in the amount of energy used by amplifier to power the speakers? it's always same for the same volume level with same signal, but it depends massively on signal and everybody knows that. --[[User:joerg_rw|joerg_rw]] 03:33, 15 May 2015 (UTC)
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It doesn't matter for the task at hand. Btw, can i subscribe to the page's updates? The "watch this page" thing doesn't seem to work. [[User:l29ah|l29ah]] 00:01, 16 May 2015 (UTC)
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And honestly when you state "A yields wrong numbers, B yields correct numbers" and somebody is challenging this statement,
 
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"CITATION NEEDED! Why should a shell script and i2cget be inferior to a perl script and a deprecated kernel module? --joerg_rw 12:18, 13 May 2015 (UTC)
 
-
then an answer like
 
-
Go measure it yourself. l29ah 23:40, 14 May 2015 (UTC)"
 
-
is neither sufficient nor convincing nor appropriate for a wiki. What makes you think *your* script is the one that has the better more accurate values? You obviously don't even completely understand the operation modes of the bq24150 chip. Hint: load your "always same mp3 file" into audacy, mark a 2.56s window at a random point of time and calculate the total energy in that window. Then move the window and see how the total energy changes depending on the segment of the song you look at. And why would any user be interested in the amount of energy used by amplifier to power the speakers? it's always same for the same volume level with same signal, but it depends massively on signal and everybody knows that.
 
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--[[User:joerg_rw|joerg_rw]] 03:33, 15 May 2015 (UTC)
 
** idle @125MHz: 45mW T
** idle @125MHz: 45mW T
** idle @250MHz: 76mW T
** idle @250MHz: 76mW T

Latest revision as of 15:40, 16 November 2024

who has created this? what about sources or describing test procedures? --ossipena 08:01, 8 February 2010 (UTC)


Moved the whole thing to discussion since that's where it belongs when it turns into a talk 

those values are moot - for the first 2 it's irrelevant which process is *idle* since the CPU should zeroclock anyway, alas here it's at fixed clock-freq which is NOT recommended. For the rest the only useful audio source to run those tests is a pink noise at 0dB. See `man sox` for how to create such file. Or to set volume to 1 step above zero, see above - so the whole music content becomes irrelevant. For arbitrary music the amplifier will introduce random "noise" up to 2000mW to the figures. The BQ27200 can't average out that noise. Further there's "GUI on" which means "backlight" and that's very random and even depending on ambient light, see 3 bullets above --joerg_rw 12:52, 13 May 2015 (UTC)
Not fixed, it's ondemand w/ bottom freqs allowed as specified.
I restarted the same track every time, so the comparison should be quite  adequate, tho a noise would be better, yep. Also, where did you get the information regarding the bq24150 performance? Such spikes (if there are any) would be smoothed by the capacitors on the power lanes and then detected by bq24150, no? I didn't get any numbers on it from the datasheets tho.
No backlight ofc.
l29ah 22:53, 14 May 2015 (UTC)



When there's GUI ON then what's the meaning of that when there's no backlight?

Huh? It's a client-server app. l29ah 00:01, 16 May 2015 (UTC) 

Generally those values over at main page are meant to be reproducable by others, otherwise they are useless. Neither a "GUI ON, BackLight Off" nor "always same (unknown) random music file" is reproducable by others.

The numbers just compare the battery-friendliness of different music players. You can retest it properly and get the same differences. l29ah 00:01, 16 May 2015 (UTC) 

And honestly when you state "A yields wrong numbers, B yields correct numbers" and somebody is challenging this statement, 
 "CITATION NEEDED! Why should a shell script and i2cget be inferior to a perl script and a deprecated kernel module? --joerg_rw 12:18, 13 May 2015 (UTC) 
then an answer like 
 Go measure it yourself. l29ah 23:40, 14 May 2015 (UTC)"
is neither sufficient nor convincing nor appropriate for a wiki. What makes you think *your* script is the one that has the better more accurate values?

I compared their output at rest and in polling mode and observed the shell script consumed noticeably more power. I doubt we're talking about the same one tho: the one i've poked was called bq27k-detail2. You can retest it yourself; i don't care much of publishing it paranoida^Waccurately, just wanted to share my results that i find quite helpful regardless the flaws you're talking about. l29ah 00:01, 16 May 2015 (UTC) 

You obviously don't even completely understand the operation modes of the bq24150 OOPS sorry bq27200 chip. Hint: load your "always same mp3 file" into audacy, mark a 2.56s window at a random point of time and calculate the total energy in that window. Then move the window and see how the total energy changes depending on the segment of the song you look at. And why would any user be interested in the amount of energy used by amplifier to power the speakers? it's always same for the same volume level with same signal, but it depends massively on signal and everybody knows that. --joerg_rw 03:33, 15 May 2015 (UTC)

It doesn't matter for the task at hand. Btw, can i subscribe to the page's updates? The "watch this page" thing doesn't seem to work. l29ah 00:01, 16 May 2015 (UTC)

    • idle @125MHz: 45mW T
    • idle @250MHz: 76mW T
    • mediaplayer mp3 playback, max volume, speakers: 415mW T
    • mediaplayer mp3 playback, max volume, headphones: 262mW T
    • openmediaplayer mp3 playback, max volume, headphones: 230mW T
    • mediabox mp3 playback, max volume, speakers: 463mW T
    • mediabox mp3 playback, max volume, headphones: 324mW T
    • oscp mp3 playback, 99% volume, gui on, speakers: 434mW T
    • oscp mp3 playback, 99% volume, gui on, headphones: 301mW T
    • oscp mp3 playback, 99% volume, gui off, headphones: 273mW T
    • oscp mp3 playback, ALSA, PA's mixer setup, 99% softvol, gui off, headphones: 195mW T
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