Optimus V Battery Drain Optimization Tests Part 2

[Superorb]

lol well if it's any consolation, it's a long distance relationship and there's no guarantee it'll work out ;-)

You get half a check added back then

 

[cpshelley2]

You get half a check added back then

thanks super, that's what i was going for haha

 

[cpshelley2]

ok, so after 12.5 hours, i had a battery drain of 30%, or about 2.4% per hour under fairly constant, heavy load. this is with gps/wifi/bluetooth disabled, moderate to heavy use of 3g, and a fair amount of texting. screen on time was about 3.5 hours. this is before i applied the tips from mmarz and superorb!! with just those results, it would take an estimated 41.7 hours to drain my battery to 0% under similar usage conditions.

right now, i'm charging back up to 100%, i've applied the changes that mmarz and superorb suggested, and i'll do the same thing again and report back on the results.

i don't know how accurate these estimates are though, since i only allowed a 30% drain.

 

[LeslieAnn]

One thing to note here.

I was running at 750/75 for a while, and while the battery life was great at idle, while streaming music or using GPS, the phone can get awfully hot. Even worse if you revert to a cheap Taiwanese battery.

I wouldn't recommend doing 200/750, but I have started using something like 400/750 and am having pretty good results. It's probably high enough to avoid the lag and ups and downs, but keeps it from running at full bore anytime some minor process is being run.

 

[Superorb]

^^ You want it to be at full speed even for minor processes since it completes work faster at the higher speed while using less power than it would at a slower speed comparatively speaking.

 

[cpshelley2]

One thing to note here.

I was running at 750/75 for a while, and while the battery life was great at idle, while streaming music or using GPS, the phone can get awfully hot. Even worse if you revert to a cheap Taiwanese battery.

I wouldn't recommend doing 200/750, but I have started using something like 400/750 and am having pretty good results. It's probably high enough to avoid the lag and ups and downs, but keeps it from running at full bore anytime some minor process is being run.

Leslie, those were EXACTLY the numbers i was going to try before going to 750/750 (the 400/750)

btw, allow me to thank you for the Aphrodite ROM, i'm using your 1.3.3/Xeonia05 ROM and it's solved almost all of the issues i was having with this phone... great ROM!!

 

[LeslieAnn]

^^ You want it to be at full speed even for minor processes since it completes work faster at the higher speed while using less power than it would at a slower speed comparatively speaking.

Sorry, I sort of thought so too at first, but but that isn't always true.
Like most things, it's a balancing act.

Some processes do not require full load, such as streaming. In order to stream you need a low amount of cpu constantly. The idea you are working from is good for things that run for a short time span, which is most processes. Streaming and navigation however require constant processor use. and letting them run rampant at overclock is just creating a lot of heat and sucking down the battery. Try streaming music and using navigation for 30 minutes and see just how hot your phone gets.

btw, allow me to thank you for the Aphrodite ROM, i'm using your 1.3.3/Xeonia05 ROM and it's solved almost all of the issues i was having with this phone... great ROM!!

Great, glad you like it!
2.0 is getting there.

 

[Superorb]

^^ Good point, I hadn't thought about things like streaming.

 

[cpshelley2]

Great, glad you like it!
2.0 is getting there.

i went with 1.3.3 with 05 because from what i could tell, it seemed to be the most stable choice.

also, what do you think is heating up the battery so much during streaming/GPS at 750/750? just the constant use of 3G and GPS at that speed?

 

[cpshelley2]

i'm thinking the 400/750 would be a good balance for what i use my phone for... i don't do any streaming or use GPS (i keep all my music on the SD card and really have no need for navigation, nor do i want google knowing where i am at all times) so i'm mostly using my phone for texting and web browsing over 3G.

 

[mmarz]

I know where you're coming from, LeslieAnn, but the problem with that logic is that it assumes SetCPU is smart enough to figure out that your CPU clock should be set to the lower speed when you are streaming. From what I've seen, this isn't the case. If there is any CPU load, SetCPU sets the speed to max. Even with the conservative governor, SetCPU will bring the clock speed to max, just at a slower pace. The end result is your phone running at the max clock speed whenever you are doing anything with it. The only thing that would reduce power consumption in case of streaming and other prolonged tasks is lowering the max clock speed. The only time the lower clock speed is used is when there is truly nothing happening.

Of course, everyone does a mix of standby, intense tasks, streaming, calls, texting..ect. So one solution isn't going to work for everyone.

 

[cpshelley2]

mmarz, do you know anything about the program i am using, the no-frills cpu app? it seems to have very few options compared to SetCPU, only allowing you to adjust the min, max, and governor (of which my available choices are conservative, ondemand, performance, and interactive)

do you know if this app works in the same/similar fashion as SetCPU?

 

[Superorb]

Just as a heads up, SetCPU is available to XDA members for free.

SetCPU for Root Users [2.1.1a] Dual Core Madness 2/27/2011 - xda-developers

 

[mmarz]

mmarz, do you know anything about the program i am using, the no-frills cpu app? it seems to have very few options compared to SetCPU, only allowing you to adjust the min, max, and governor (of which my available choices are conservative, ondemand, performance, and interactive)

do you know if this app works in the same/similar fashion as SetCPU?

It should work the same way even if it doesn't have a few of the options SetCPU has. The actual clock handling is done by the governors which are built into the Kernel. SetCPU and the app you are using merely adjust the control values that the governor uses. You could do the same with a text editor if you knew where those configuration files were.

 

[mmarz]

I know where you're coming from, LeslieAnn, but the problem with that logic is that it assumes SetCPU is smart enough to figure out that your CPU clock should be set to the lower speed when you are streaming. From what I've seen, this isn't the case. If there is any CPU load, SetCPU sets the speed to max. Even with the conservative governor, SetCPU will bring the clock speed to max, just at a slower pace...

I just did some tests, and I am wrong about this. If you set your lower clock speed too low and then try to stream audio, the clock speed will jump to the max value (if not permanently, then frequently). But if you have the lower clock speed set to ~600 and above, the governor is smart enough to figure out that 600MHz is doing the job and will leave the clock speed there. So there is an advantage to setting a lower clock speed when doing streaming/time dependent tasks, but only if that lower speed is fast enough for the task at hand. If the clock is set too low, the governor will default back to the max clock speed.

Aww man this is getting complicated.

I feel like we need a double blind study with 10 phones and a few months of data to get to the bottom of this....Or you guys can post your phone usage results.

 

[cpshelley2]

superorb: thanks for the heads up!! i probably would've never found that on my own!

mmarz: i agree, lol -- could you recommend a simple, free app that would display my current CPU frequency so i could do some testing at different threshold values/governor settings? i've been searching the market for something, all i really need is an app that displays the current frequency

 

[cpshelley2]

i just found something called CPU Spy that shows you the time spent in each CPU state, and the results are kind of interesting. these are my results for the the 122/729 configuration i was running for the past 14 or so hours:

729 -- 0:43:13 / 5%
600 -- 0:03:11 / 0%
480 -- 0:03:58 / 0%
320 -- 0:02:45 / 0%
245 -- 0:07:54 / 0%
122 -- 1:11:45 / 8%
deep sleep -- 11:56:33 / 84%

i'm surprised to see that it's using the states in between my min and max, and not simply alternating between them...

 

[cpshelley2]

mmarz: you seem to get pretty good battery life with 3G on all the time and moderate usage... would you think it would be more of a draw on the battery to have 3G on constantly, or to have the 3G radio constantly connecting/disconnecting every time i turn my screen on/off to answer a text?

 

[mmarz]

mmarz: you seem to get pretty good battery life with 3G on all the time and moderate usage... would you think it would be more of a draw on the battery to have 3G on constantly, or to have the 3G radio constantly connecting/disconnecting every time i turn my screen on/off to answer a text?

That's a good question. I don't know if it does draw any more power switching it on or off.

From my tests, you save no extra power putting your phone into airplane mode vs 3G and cellphone activate but no data or calls being made.

When you are connected to a tower, you either have access to 3G, or you don't. I would think that enabling/disabling 3G merely tells the phone whether to use that access or not. It might cost you processing power, but I don't think the radio is used until you start to transfer data.

I think what might be costing you way more energy is the 800 daily texts

 

[mmarz]

superorb: thanks for the heads up!! i probably would've never found that on my own!

mmarz: i agree, lol -- could you recommend a simple, free app that would display my current CPU frequency so i could do some testing at different threshold values/governor settings? i've been searching the market for something, all i really need is an app that displays the current frequency

What's wrong with this app: [APP][2011/03/22][1.9] "NoFrills" CPU Control: configure cpu frequencies & governor - xda-developers