Originally Posted by Ubizmo
So if I set some other launcher as the default Touchwiz goes away, but does it still use CPU and RAM?
No, and yes, but not in the way you think.
Android is not windows, or whattever. Your phone is not a desktop.
Say that a few times.
Let's address the easy part by going back in time with Android a little bit. I don't know how things were back in the original days, but when I first started using an Android phone it seemed like everyone out there was obsessed with battery life, and hated apps that "drained their battery".
Somewhere out there, is some guy doing coke of a model's uhm, backside, because they got rich from writing the first task-killer app.
People know that with a computer, if a program is open, it takes up resources. They assume the same logic is true with their phone.
What they forget, is that Android and other systems like it, were designed with the fact that they run off batteries, and have significantly lower specs. Not only do they have far less OS overhead, but they manage the other resources such as RAM much more efficiently.
Because they have to. Seriously, I'm sure the Samsung Galaxy S3 is a crazy fast phone, but just because you might have a computer, even a very old one with fewer cores, and a slower ghz rating........doesn't mean anything. If you somehow put the two in a head to head competition, even a $400 crapbox special would smoke the living daylights out of the phone.
With Android, if a program is in open memory, it is there for one of two reasons. It might actually be running. For example the clock, will almost certainly always be running.
Or it might be another app, that is frequently called by other apps. Android is designed to keep things in memory that have been opened recently to CONSERVE BATTERY LIFE. If it's in memory and not doing anything (such is the case with probably 50% of the processes in your phone) it is not........using the CPU in any way, whatsoever. But if that app is needed for whatever reason by Android or more specifically, by another app, or as a result of another app, Android will re-open it. Technically, that action uses cpu cycles.
Bah, forget all that, here's a much simpler way to explain it. Right now I have about 750megs of free "ram" in my phone, this seems to be about normal for me.
If I were to go to the market and download a bunch of really large applications that number of course would drop.
Would my battery life drop, assuming I used my phone in the exact same way and I never used those programs?
Most importantly.........just don't worry about the performance issues. The phone is fast, crazy fast, especially for how affordable it is. It's a beast.
As for battery life, it's really simple. The only things that really make a SIGNIFICANT effect on your battery life is how big the screen is, how bright you have the screen set for, how often the phone is sending or receiving wifi/mobile data, and how often it is vibrating.
For phones in this screen size, don't expect to be able to watch the first season of Battlestar Galactica on a single charge and you'll be fine.