[Samsung Infuse 4G] electricpete1:
Seems like some recurring discussion in past threads:

1 - why should we even bother overclocking if we’re not a gamer.

2 - won’t we damage our device with overclocking.

I haven’t seen definitive answers posted anywhere, and I certainly don’t have one.

Maybe in that case (I have no definitive answer), I should probably just keep my mouth shut.

It may be the case, if so let me know.

For whatever reason, I have some strong opinions and I feel it would be useful to share my opinions and the reasons I have formed those opinions.

Take them or leave them or add to them... up to you.

Point out to me if you think I am grossly mistaken.

There is constant tradeoff between battery and performance.

Underclocking will help you save battery. How low you want to underclock depends on what you can tolerate.

But what you can tolerate depends on your user experience, which can be dramatically impacted by use of overclocking at other times.

The perfect example for me is a program which is slow to start up. In my case it is Memento database with 1000+ records, takes a long time to read in (I think the program does some sorting every time it opens). That is a minor annoyance. If I were to underclock it will start even slower, I’m going to get impatient and set my speed back up.

But think about this:

1 - Using Tasker you can apply cpu profiles upon application launch and remove them after a predetermined length of time. I can give the program a blast of 1600M-hz when it starts, then set it back where it was after predetermined period (for example 10 seconds).

2 – Setcpu is not quite as flexible as tasker in this regard. With setcpu we can create a profile to occur when we launch the program like Memento, but we just can’t incorproate a time delay into the logic (it will stay on the higher profile as long as the program runs in the foreground).

3 - There may be circumstances where this setcpu behavior is what you want... it will give you faster response whenever the program is in the foreground, and will yield to lower priority profiles whenever the program goes to the backghround.

(I haven’t investigated how to make make Tasker and setcpu play nicely together yet).

So, if you speed up the things that cause noticeable delay for only a short time, or particular applications which seem to run slow then you can probably be more satisfied with your underclock in the other times. In the overall picture, I think the overclock capability can ironically be used as part of a strategy to save battery (unless you just like overclocking just to see things zip accross your desktop and menu’s pop in and out faster than you can blink, I’m starting to get spoiled with that behavior on my phone in its new configuration, partially from overclock..I’m sure others get even better in their configuations..).

On this I would say no, as long as you are careful about not running it in conditions that create high temperature. .

(you may have stability problems as you guys know, an entirely different subject).

The physics of the damage are all related to temperature. There are many variables affecting temperature that the designer is unaware of and so he builds in margin for the worst cause unknown future occurence (he has to consider maybe phone will be in desert with 100F ambient, and on the charger, while the user tries some heavy surfing with gps, all at the same time, so he limits cpu to 1200Mhz).

We on the other hand know what are the conditions of our phone and what it’s likely to see and what it’s doing at any given time, and setcpu provides additional ability to monitor and adjust.

Here are example setcpu profiles I came up with to protect myself from damaging temperatures (Zen's kernel A/1600)

Priority 100: If batter temperature > 50C (122F),establish conservative governor 100-400Mhz

Priority 90: If batter temperature > 45C (113F),establish conservative governor 100-800Mhz

Priority 80: If battery temperature > 40C (104F), establish conservative governor 100-1200Mhz (in the event I was overclocking, this profile will stop it when battery temp exceeds 40C, all other profiles that may invoke overclocking are lower priority than 80).

This is just from judgement, knowing that I’m normally < 104F battery temp during light use and don’t want to overclock when I’m outside that normal light use zone. Some further curtailment of cpu max frequency occurs as battery temperature climbs above that. (which I would not have even had the benefit of if I were casual user with no overclocking and no setcpu).

As long as you’re limiting temperature, you should not be worried about damage imo. By the way, of course overclocking is not the only thing to affect temperature: things like phone case (thermal insulation), charging, gps, heavy use etc all have an effect. I'm not quite sure why sometime cpu overclocking gets singled out in a dangerous category all its own without any discussion of other things that affect tempertaure.

In fairness, you may point out that what we monitor is battery temperature and not the same thing as cpu temperature. It’s a good point. Increase in heat generated at the cpu causes more of an increase in temperature at the cpu then it does at the battery. But it's question of how much different. there's a matter of how much. Why do you think it is that Samsung didn’t give us cpu temperature indication? I think because they knew battery temperature is close enough. Even on newer flagship Behemoth Samsung Note, I’ve read you still only get battery temperature, no cpu temperature. If cpu temperature was that much different, they surely would have provided a separate indication of cpu temperature (cpu is after all a much more critical component than replaceable battery).

And why should we expect battery temperature to be representative of cpu temperature on our phone, when the same is not true on a pc? I think I can answer that:

* PC has things all spread out. There is air flowing through. The air picks up heat from each component from heat sinks by convection. The component temperatures are not tightly coupled together.

* Phone (in contrast to pc) has everything compact inside one itsy bitsy case. There is no air flowing through. That means heat transfer inside the phone is not by convection but by conduction. For most effective conduction, all components are attached with high thermal-conductivity path to the phone structure and the exterior surface of the phone. The heat transfer from phone to ambient is primarily convection. So we have effective heat transfer (conduction) among the components of the phone and less- effective heat transfer (from phone to environment). It tends to tell us that there will not be big difference in temperature among phone components. The big temperature difference that occurs is between the phone and the ambient air.

I don't have access to a phone which has both cpu and battery temperature indicators. If someone does, it would be interesting to hear how close those two temperatures follow each other.

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Edited to add: searching other threads suggests there can maybe be a substantial differencebetween cpu temperature and battery temperature. That makes me a little less certain. At least we can use battery temperature as a gross indicator that the cpu isn't seeing excessive extra heat from other non-cpu sources while we're overclocking it. Certainly having profiles in place to limit overclocking when battery temperature is high can only help protect us. But is it a false sense of security which can lead us astray? I dunno. I have already done a stability test at 1600 for quite awhile and there's no damage in sight, so if there is any damage potential, then it is only an accumulation over time. I don't plan on leaving Fmax at 1600 all the time anyway, since it would kill the battery. My planned strategy reserves the 1600 overclock for occasional playing around, and boosts when I need them like like my Memento database. My gut says that approach is just fine. Interested in hearing any other thoughts, experiences, links that may shed light.