[EVO 4G Android Development] jklong03:
Colorized-vs-Minimalistic Themes and Battery Usage

NOTE: this is a long post, so please don't "Quote" it unless you need too. Just reference my "diatribe" or "jklong03's Rant about battery usage"..etc....

So Here we go:

I love the Minimalistic Theme so far!! That is just my opinion, because I like "simple and clean" and nice defined fonts and icons.

However, I have heard some people state that these will be more "battery friendly". Below is "my opinion" why this fact is not really a true statement (IMHO) and that these "clean" Themes will not use less battery than a regular theme with colorized icons and displays.

I can't say I speak with any official knowledge of how HTC implements their displays, I can only talk about the basic science involved and how that does/(doesn't) really impact battery performance. This is based upon 20+ years experience in Electrical Engineering and my 18+ years of education in the basics of this subject (Masters Degree in Electrical Engineering, Specialized in Communications and Radar devices, but that's not important right now, and "Don't call me Shirley!")

A TFT ("T"hin "F"ilm "T"ransistor) display like the one on our phones begins with its "back-light" LEDs. These provide a source of broad-spectrum light which is directed out of the display screen. Then, the LCD's, as we incorrectly call them (really a TFT, but that isn't important right now, and "I just want to say we are all counting on you") aspect kicks in. These are switched on in different configurations to allow a certain spectrum of the "LCD's backlight" to escape to our eyes.

(As an aside, that is why your screen appears washed out in bright daylight. It isn't that the display isn't "reflecting" enough light to your eyes, it is that the display can't "force" enough light out of it to overcome the surrounding sunlight and reflections, when you adjust the "brightness" on the phone, you are really controlling how "bright" the LED background lighting (and therefore how much battery it uses by the way) is and therefore how much light that is filtered by the TFT's on top of it, is allowed to pass through the TFT display into your eye).

So, with that brief background on how TFT displays work I would state the following general rules of thumb about Themes:

1) Your screen "brightness" setting is more important than "Color"

2) A B/W Theme really won't save any appreciable battery, because the power to turn on a "Black/White" TFT Crystal isn't that much different than that required to turn on a "Green" or "Red" TFT Crystal (and turning on the Crystal means allowing that color of the back light LED to shine through the display and reach our eyes).

3) Therefore, a "minimal" or B/W Theme won't affect your battery drain any better than a full-color one will!

Now, realizing that simply displaying "color" doesn't really drain an EVO faster than "plain-Jane" displays do, I can't speak anywhere nearly as informed on what the Software (and therefore the CPU loading) effects of rendering a colorized-vs-B/W display may be. It is entirely possible, that even with all this science behind the operation of a TFT display like that on our EVOs, that the "software load" required to display colorized displays may prove to be enough that we will see better battery performance with a B/W basic Theme than with a Full Color Theme. I just wanted to clear the air regarding actually displaying those color physically. (this is an age old argument between "Hardware" guys and "Sofware" guys, and will probably never be completely solved by the way!!

Anyway, that is my position on this issue...."My Name is Jeff...and I approved of this message".