[Defy Android Development] .dredd.:
hottracks4:

"It means that it will stay at higher frequencies for lesser amount of load, i.e., when the higher frequency's is not even required.. Leads to heating mainly which over time will spread to other parts of the phone.."

This is what theoretically could be true but it is not word by word.

What generates the heat? It is the current flowing through the circuits. CPU is more difficult of course but surely the more current it requires the more heat it generates.

Let's make an analogue with car engine. If you want to go from A to B which method is easier for the engine:

1. Go at first gear most of the time at high rpm and only if it excesses 90% of engine's max. rpm you shift up to second gear.

2. Start at first gear and when more speed needs you gear up at 50-60% of engine's max rpm. (which is more or less the normal driving practice)

Which method consumes more fuel? Which method generates more heat in the engine?

Back to cpu... a lot of users experienced using cpu monitor apps like cpuspy that with factory cpu settings (300, 600, 800 MHz, threshold 86%) the cpu works at 300MHz most of the time of usage... which means that you have a 300MHz Defy... :confused::D

Moreover, some users experienced also slow wakeup when a call received or slow responses in other circumstances... even freezes in some conditions. These are results of high threshold... the cpu is not able to do its job at 300MHZ in time but is not allowed to gear up to next clock only over 90% of load... therefore the tasks will be done in longer time or freeze due to delays. Supposed that everything is alright with the rom these malfunctions and lags are all results of the high threshold.

Giving a higher clock to cpu does not mean that cpu will require more power... as said the clock is one thing and cpu load at a clock is the other. However the cpu requires higher vsel at higher clock but requires less current due to the lower load... because the tasks can be solved faster and easier at higher clock resulting in lower cpu load.

Lowering the threshold results in lower cpu load at all clocks which means lower current required at all clocks and also results in faster responses to tasks.

I talked to a user yesterday morning on an other forum who claimed many freezes a day... he used his defy at 90% threshold. Then he did nothing else but lowered the threshold to 70% and in the evening he reported no freezes anymore.

Furthermore... if you use lower threshold which means lower max load at a clock,

theoretically

you can use lower vsel also because lower vsel would be enough let's say up to 50% of load. Please consider that I never tried this... but it should work.

"Any excess heat means that the life span of the device decrease.. Nowadays it may or may not matter much due to advancements in the field of technology but why take the risk?

Forget the phone, the heat may even harm you, for example if you're wearing Jeans or something similar, there have been cases where phones have blown up, caused burns etc due to friction and combined overheating of the phone.. Rare possibility again, but are you willing to take that chance? Better to be safe than sorry i say.."

As mentioned before the heat depends on the current and not the voltage (vsel). If your phone idles e.g. at 450MHz instead of 300MHz it means that it does the background tasks quicker and easier during idle and won't generate more heat.

"And lastly, it will drain battery which is our main concern.. Higher frequencies mean it's at a higher vsel most of the time, therefore higher battery consumption.."

The users who lowered the threshold haven't experienced more battery consumption but faster operation and better responses. Logically the lower threshold does not necessarily brings higher consumption because the lower current rates at clocks. Most of the cases poor battery performance is a result of bad roms, background apps or other causes.