PLEASE READ: Do NOT worry about Apps running in the Background

[bradpr]

Moto Droid's memory should not be using power to retain data. It's using flash memory which is a non-volatile memory that will not wipe data when there is no power. I would expect that's the natural choice for PDAs and phones like this that depend on long battery charge life.

You're describing something that is sound in theory, but I don't think it works that way in reality. Assuming that the RAM on the Droid is flash, then for a program in memory to behave the way you're proposing, the little piece of memory it occupies would have to be on a memory unit dedicated to that program. That's the only way the memory it is occupying could be powered off to save power when the program is idle. I think the reality is that the memory module in the Droid is shared by all programs. Therefore, our idle program is consuming power by simply being resident in memory. Furthermore, the memory management function of the OS will consume power managing the memory resources occupied by idle program.

Again, I don't know this is how the Droid works. I'm just talking from knowledge of how computing machines work in general. If the Droid has some new memory technologies, I'd really like to read more about them. So, please share your sources!

 

[alienware777]

Finally people are told this... It gets so annoying to see again and again about killing apps.

 

[mikes]

I think the reality is that the memory module in the Droid is shared by all programs. Therefore, our idle program is consuming power by simply being resident in memory. Furthermore, the memory management function of the OS will consume power managing the memory resources occupied by idle program.

:icon_rolleyes: RAM doesn't consume more power depending on what it holds. The RAM is powered anyway, so it might as well hold data for an app, so the app can start up again quicker.

There may be a small number of additional cycles for the CPU to manage more memory blocks, but management is only happening when things are changing dynamically, other apps running/opening/updating, etc. The additional effort put toward memory management would pale in comparison to the activity which is causing it to happen.

 

[bradpr]

There may be a small number of additional cycles for the CPU to manage more memory blocks, but management is only happening when things are changing dynamically, other apps running/opening/updating, etc. The additional effort put toward memory management would pale in comparison to the activity which is causing it to happen.

I agree with you, RAM is always powered up, so simply storing something in it doesn't take up power, but also as you correctly stated, MANAGING that data does.

A program running in memory requires CPU cycles for memory management and depending on what kind of program it is can require substantial resources to simply sit there and do nothing. Consider an application that monitors the WIFI radio for AP names - it doesn't require user interaction, but can suck up a ton of power querying the radio.

I've asked a few times with no response, so I'll ask again. I want to think that Google has done something revolutionary with the Droid, so PLEASE show me the technical documentation that describes this super efficient system resource management technology! Until I see it, though, I have to assume that its just as inefficient as any other smartphone OS out there. The battery life on my Droid is no different than the life on my Windows Mobile, so I am extremely skeptical android has any exceptional memory/battery management enhancements. Please prove me wrong!

 

[bradpr]

Wierd behavior from flash based RAM

Moto Droid's memory should not be using power to retain data. It's using flash memory which is a non-volatile memory that will not wipe data when there is no power. I would expect that's the natural choice for PDAs and phones like this that depend on long battery charge life.

Mr Sentient,
Here's something interesting I just observed - I took my battery out of the Droid while it was powered up. If its system state and RAM are truly in non-volatile memory, it should return to the exact state it was in when i pulled the battery when I put the battery back in, right? Contrary to that theory, it doesn't. It reboots. Why is that so if everything is in non-volatile memory requiring no power to be preserved?

 

[mikes]

A program running in memory requires CPU cycles for memory management and depending on what kind of program it is can require substantial resources to simply sit there and do nothing. Consider an application that monitors the WIFI radio for AP names - it doesn't require user interaction, but can suck up a ton of power querying the radio.

An "application that monitors the WIFI radio for AP names" doesn't "simply sit there and do nothing." I thought this was about idle apps.

 

[davidtaylorjr]

This is great information. I read this over a week ago and immediately quit worrying about apps. I have NOT notices a decrease in speed, battery, or any other performance of the phone. It takes care of everything! Great post!

 

[richelesro]

I have to disagree with this thread too. The email application on my phone will eat my battery inside of five hours if I don't kill it. That may be because I have a very active Exchange account, but it demonstrates the point that some applications can kill the battery under certain circumstances. If I find that the battery has hit 50% in a couple of hours, I kill all applications and the phone remains with some charge for the rest of the day.

 

[davidtaylorjr]

I have to disagree with this thread too. The email application on my phone will eat my battery inside of five hours if I don't kill it. That may be because I have a very active Exchange account, but it demonstrates the point that some applications can kill the battery under certain circumstances. If I find that the battery has hit 50% in a couple of hours, I kill all applications and the phone remains with some charge for the rest of the day.

That would be an uncommon circumstance. I get tons of email a day on my gmail account and have tons of battery life. You would be what I refer to as a "power user" not normal user.

 

[mikes]

I have to disagree with this thread too. The email application on my phone will eat my battery inside of five hours if I don't kill it.

Well, that's by design. It will wake up and use processor and network to check/get new email. Your choice - keep up-to-date on email, or don't. Did you try changing the email app to only check once an hour?

 

[bradpr]

An "application that monitors the WIFI radio for AP names" doesn't "simply sit there and do nothing." I thought this was about idle apps.

Yes, but that's an example which should make my point easier to understand. The theoretical WIFI app sits in the background, consuming power. Just like the email application that Richelesro referenced. Just like any application that sits in the background, they all consume resources. The point is applications can sit in the background and burn the battery. Respectfully, until someone explains (instead of simply asserting) how the Droid's OS is so efficient that users don't need to monitor what's running, I'm unconvinced that it runs the way the moderator and several posters claim it does. As further evidence to back up my point, the battery life on this phone is just as crummy as the battery life on windows mobile devices or the IPhone or any other 'smartphone' that has ever existed. Why wouldn't these vast improvements of resource management make the Droid a better performing smartphone than its competitors?

 

[richelesro]

That would be an uncommon circumstance. I get tons of email a day on my gmail account and have tons of battery life. You would be what I refer to as a "power user" not normal user.

GMail and Email are different applications...

Did you try changing the email app to only check once an hour?

I have it set to 30 minutes, not push.

 

[davidtaylorjr]

That would be an uncommon circumstance. I get tons of email a day on my gmail account and have tons of battery life. You would be what I refer to as a "power user" not normal user.

GMail and Email are different applications...

My point was that gmail is pushing as well, constantly checking.

How old is your droid? Has the battery been conditioned yet?

 

[bradpr]

I have to disagree with this thread too. The email application on my phone will eat my battery inside of five hours if I don't kill it.

Well, that's by design. It will wake up and use processor and network to check/get new email. Your choice - keep up-to-date on email, or don't. Did you try changing the email app to only check once an hour?

Absolutely - its an app that runs in the background and uses resources, and it was designed to do it just that way. How do you know that other apps you have on the device aren't doing the same thing? The only way to know for certain is to monitor what's running when you think the device is idle. When I check what's running on my phone, I see numerous apps running that have no reason to be running. Who knows what they're doing when they're running when I'm not around? They may be doing nothing and only consuming a trickle of battery power or they may be brute forcing triple DES encryption on a top secret spy file. Its simply good housekeeping to monitor running processes, and it is only logical that this regimen will ultimately conserve power either by keeping wasteful processes down or by cluing you in on which processes are running in the background too often so you may uninstall them.

 

[richelesro]

My point was that gmail is pushing as well, constantly checking.

How old is your droid? Has the battery been conditioned yet?

GMail is not the application using the battery, it's the Email application. When I go to "Battery use", the Email app shows up using over 80% of the processor. The GMail application is typically less than 1%.

I bought the Droid the day it came out, so the battery is not new.