04-26-2012 03:52 AM
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  1. LeslieAnn's Avatar
    There is a lot of bad information about this, so I hope this will straighten things out some.

    ** Note**
    While new info has shown some of the finer details of this to be incorrect in places, in terms of how to overclocking is concerned, the info is still good. I will try and correct the bad parts later.


    Yes, this is a wall of text, there is a lot to cover.
    Overclocking can be simple or complex, depending on how well you want to do it. Doing it well means a faster phone with more battery life (yes, you can actually gain battery life through overclocking!) or you can do it bad and end up with a somewhat fast phone, that sucks down batteries. The devil is in the details and I bet a large amount of you are doing it wrong.


    A lot of good and bad information came almost a year ago when Mmarz did some serious testing with his OV. The testing was good, but missed a few things that were later covered in the thread. The problem is, too many people read only the first post, which was missing a great deal of information later learned. Because of this, we often have two camps of overclockers with the OV, those who read the thread and understand it, and those who skimmed the first post and/or were handed bad information. This is an attempt to clear all of that up once and for all.



    First off we need to get the basics about of the way.
    Your phone essentially has three speed settings and two voltage settings. Voltages are split at 480mhz, 480 and below uses a lower voltage and anything above 480 uses a higher voltage. We have no way to adjust this so don't bother asking, the phone supposedly doesn't support it. Then you have the three processor speeds, idle or sleep mode, low speed, and high speed. Idle or sleep mode is obvious, it's when the screen is off, low speed is for low cpu intensive tasks, such as music or gps or just any task that doesn't require full cpu power, then finally we have high speed for anything requiring hardcore processing. Idle speeds you can't control, so we'll focus on the other two.


    Let's start with high speed since it's easier to understand (though most get it wrong).
    This is obviously your max overclock setting, while people focus on it most, it's also the least important of the two settings. Now many crank up this number until it seems to not crash to make the phone as fast as possible, unfortunately, this is actually wrong. Just because it seems stable, doesn't mean that it is. We often hear of people having really high overclocks saying they are stable, EXCEPT for that one app. No, you aren't stable.

    What is happening is that the system is compensating for errors. These errors finally overwhelmed the system and caused the app to crash. This is why we say two notches below "max stable". See, we don't have a program to verify how many errors we are getting, but there is another way, we use a benchmarking tool. When you get an error, the phone has to compensate and redo that calculation, which takes time and slows you down. Over time this has been turned into an easy to follow rule, two notches below your max stable speed which is about where speed vs error rate becomes bad. Some of the apps that fall prey to this first is Gallery, and the camera. Those crash more often than the rest due to overclock, however, Gallery can be pretty unstable even in the best of times so don't base your overclock stability on it alone. There are a few other common ones, and as I come across or remember them I will add them here.

    Ironically, this has also been shown to be the most efficient for batteries as well, yep, overclocking can improve your battery life! Amazing right? Every time you make a processor go faster, it uses more amperage, the voltage is the same but the amps go up (it's a law of computing). The faster you get work done, the faster you can return to idle, however, there is more to it than that. First you have errors, those suck down battery and do nothing, and then you have the law of diminishing returns. At some point you are using more amps than you are getting work done. Again, two steps down from stable has shown to be the most efficient for getting work done done the fastest, and gives you the best battery life. This has been born out in benchmarks several times.


    Low speed (minimum clock)...
    Many people set this as low as possible and think they are all set, unfortunately not only are they wrong, but this is also the most important setting. Before I go any further I want to say one thing... The OV does NOT support 122mhz, setting your phone to that is pointless, it will simply not work. So what is it defaulting to? I can't be certain, but I suspect it probably goes to 240mhz, regardless, it doesn't work.

    Now, there is some debate on the low setting.
    We don't know for certain if the phone scales between idle and minimum. In other words, if your minimum is set to 480, does the phone only use 240 when needed or does it automatically use 480? What we do know, is that there is no scaling between minimum and maximum. In other words, once you exceed your minimum, even by one mhz, your phone will spike to full speed. Let that sink in and remember that, it's extremely important.

    So let's say you set your phone at 240 minimum, and you decide to stream Pandora and use Google Maps, 240mhz is not enough, therefore your phone will go to whatever your maximum speed is. The problem with this is that we aren't compressing a file which has an end point, we are using low power items over an undefined period. During this time your phone is running away using as much power as possible. This means your battery is draining and just creating heat, which only hurts your battery more.

    How high you set the minimum and exceed it also matters because the lower you set the low, the worse this gets. Say you set the minimum at 240 and you use 241 and your phone spikes to a max overclock of 740, that means your phone is burning off 500mhz, compared to had you set your minimum for 360 where you would only be burning off at most 119mhz because it would at most be using the 360 setting if the cpu doesn't scale, if it does scale below minimum speeds, you wouldn't burn off anything. Interesting to note here, if the cpu does scale below minimum, then 480 would be the optimal minimum setting no matter what you do since it would scale up to that point then jump.

    If you think that is bad, it gets worse, there is evidence to show that the phone will stay at peak, until ALL of the processing is done. So if you are streaming and using navigation and your phone spikes to 804mhz, even if you turn off streaming, the phone can stay at 804 until you stop navigation as well. In other words, you really don't want to exceed your minimum.


    Now you can see why this setting is so important and why we say just use 480 if you are unsure. If you can get by on a low minimum, great, that is best for the battery, but the moment you cross that, you really start sucking down more juice. It's a trade-off, higher risk can equal big gains or big failure.

    With all of this in mind, we can sort of figure out a basic plan.
    Set your high as mentioned above, that part is simple. For lows, there are some general guidelines, but remember, these are only a basic guide, you may need to experiment a bit. If you are unsure, just set your minimum at 480, it's safe and we know it works well for most people. You may not get the very best battery, but you also are less likely to let loose a battery vampire.

    For those willing to experiment, here is the basic guidelines I recommend and have worked for others:
    (Set these for what you use MOST)
    240mhz is fine for just just playing MP3's, browsing, things of this sort.
    360mhz is better suited to streaming OR possibly navigation
    480 is better for things like nav and streaming together.

    I use and recommend 480, though my phone tends to get hot when doing this regardless. Keep in mind these are only suggestions and what works best for one person may not be best for another and some apps are also better or worse than others.
    03-28-2012 04:11 AM
  2. anthonycr's Avatar
    Question: what is the point of an interactive governor of the CPU automatically spikes to full speed when the minimum is exceeded? I thought the governors could scale it up or down at different speeds, which if true would mean that it doesn't spike depending on the governor.

    Sent via the Postal Service
    03-28-2012 06:45 AM
  3. flapjack.fiasco's Avatar
    Question: what is the point of an interactive governor of the CPU automatically spikes to full speed when the minimum is exceeded? I thought the governors could scale it up or down at different speeds, which if true would mean that it doesn't spike depending on the governor.

    Sent via the Postal Service
    Did you read her post? Our processor is simply not capable. Sure it has an interactive governor, but our processor has very limited scalability, if you even want to call it that.

    You thought that the interactive governor worked one way, but as LeslieAnn has explained in great detail, it simply does not work that way.

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    03-28-2012 10:53 AM
  4. anthonycr's Avatar
    I did in fact read the post...

    Thanks for explaining though, I must have missed what she said.

    Sent via the Postal Service
    03-28-2012 10:59 AM
  5. flapjack.fiasco's Avatar
    Sorry, I wasn't trying to be rude, there is, admittedly, plenty to absorb in that post.

    By the way, this should be a sticky for sure.

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    03-28-2012 11:35 AM
  6. cole2kb's Avatar
    Yeah, I read the whole thing and didn't see any mention specifically of governors, but I did walk away with a better understanding of things. Thanks, LeslieAnn!

    Also, what does the SmartassV2 governor do for us / why is it your recommend choice for Harmonia 2? If our CPUs can't scale and only run peak / off-peak / sleep, does it really matter which ones we use?
    03-28-2012 01:59 PM
  7. flapjack.fiasco's Avatar
    http://forum.xda-developers.com/showthread.php?t=843406

    This doesn't answer your question about smartass, but it should provide some insight.

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    cole2kb likes this.
    03-28-2012 02:29 PM
  8. LeslieAnn's Avatar
    Yeah, I read the whole thing and didn't see any mention specifically of governors, but I did walk away with a better understanding of things. Thanks, LeslieAnn!

    Also, what does the SmartassV2 governor do for us / why is it your recommend choice for Harmonia 2? ?
    You're welcome.
    I obviously don't have every bit of info on everything (does anyone?), but I tried to break things down as much as I could. Getting into governors would have meant an even larger wall of text, and is out of the scope of my knowledge. I simply haven't studied it enough and really am not that concerned with it.

    I recommend Smartass V2 because it has been shown by others (who do know that system) to be the best for most people, same as 480 has.

    While some of this is speculation, the ideas and practices described, have been shown to work for people over time.
    03-28-2012 03:32 PM
  9. anthonycr's Avatar
    So basically, as I noe understand it, the scalability and governors simply scale between the limited available frequencies? I guess that's what I thought before.

    Sent via the Postal Service
    03-28-2012 06:34 PM
  10. EarthnFire78's Avatar
    The process in the V does scale, it scaling is limited to 8 steps however, but it does have a very good Deep Sleep Mode.
    03-28-2012 06:50 PM
  11. anthonycr's Avatar
    The process in the V does scale, it scaling is limited to 8 steps however, but it does have a very good Deep Sleep Mode.
    You know your stuff earthnfire

    Sent via the Postal Service
    03-28-2012 07:59 PM
  12. flapjack.fiasco's Avatar
    You know your stuff earthnfire

    Sent via the Postal Service
    Yes it does scale, but not necessarily dynamically. We know that it doesn't scale between min and max, but possibly between min and sleep/idle.

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    03-28-2012 10:23 PM
  13. flapjack.fiasco's Avatar
    The process in the V does scale, it scaling is limited to 8 steps however, but it does have a very good Deep Sleep Mode.
    How do you define "very good" deep sleep. I mean, I wasn't aware that there were varying degrees of doing nothing.

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    03-28-2012 10:27 PM
  14. Dannemand's Avatar
    Great info. Thanks LeslieAnn.

    Actually, Smartassv2 will scale and use all the speed levels you see in the menu - even ones below the Min setting. It also doesn't rely as much as the Interactive governor on user interaction to ramp up. And it DOES scale down again even after spiking to Max (I've seen it).

    CPU Spy (from market) will show how much time the CPU spent at each speed level since last reset of the counters. It's a great way to determine if your Min setting is too low for your background tasks (causing it to jump to higher speeds, which you don't want). It's also a great way to study how the different governors work.

    Unfortunately there is no way (that I know) to see if your Min setting is too high for your background tasks - you just have to try and lower it, run for awhile, then check CPU Spy.

    And finally, after some tests I made today (posted in the IHO thread) I believe it's a myth that OV doesn't support the low CPU speeds. It DOES measurably run slower at those speeds - in the case of 122 so slow that I would consider it useless. Also, depending on your governor, CPU Spy clearly reports that the phone spends time at that speed.

    Thanks again LeslieAnn, you wrote another sticky candidate
    03-29-2012 12:51 AM
  15. JerryScript's Avatar
    Unless you perform those test on each and every kernel, they are irrelevant to anyone not using the same kernel as you are.

    One kernel may be able to go down to 122, while perhaps the stock kernel couldn't? Zefie's original comments were made in the beginning of OV kernel development, so things could easily have changed.
    03-29-2012 12:55 AM
  16. LeslieAnn's Avatar
    Great info. Thanks LeslieAnn.
    Thanks, I saw your test results, awesome work, the more info the better.

    What I wrote may not be 100% perfectly accurate (it was based one what I have read in the past, and obviously things change as we learn more), but it's enough to get people pointed in the right direction for overclock and battery life.



    Zefie's original comments were made in the beginning of OV kernel development, so things could easily have changed.
    They may have, what I wrote was based on a lot of older info, but really there hasn't been a whole lot of new info since.
    Dannemand likes this.
    03-29-2012 01:00 AM
  17. LeslieAnn's Avatar
    I added a note to the first post stating that while not every detail is accurate (I stated from the start that some of it was theoretical), the basic premise for overclocking remains the same.

    I'll update the first post at some point with the new info.
    03-29-2012 01:08 AM
  18. Badboytoast's Avatar
    Thanks leslieann This is great info!!! I may not have know this about overclocking/underclocking, but now Ian some what more educated! once again thanks for taking your time! To write this !!!
    03-29-2012 01:17 AM
  19. Eollie's Avatar
    Unless you perform those test on each and every kernel, they are irrelevant to anyone not using the same kernel as you are.

    One kernel may be able to go down to 122, while perhaps the stock kernel couldn't? Zefie's original comments were made in the beginning of OV kernel development, so things could easily have changed.
    I added a note to the first post stating that while not every detail is accurate (I stated from the start that some of it was theoretical), the basic premise for overclocking remains the same.

    I'll update the first post at some point with the new info.
    Leslie I quotes Jerry because he brings up a good point. Also people need to understand each phone is different. That is well documented in the various complaints/discussion between the min/max discussion.

    What you posted is a very good starting point. I wish I could find the post Blarf made about the governors and clock speeds. It was explained well enough that the new people could comprehend it.

    Regarding the 122 debate. Yes the phone might drop to that setting but Dane showed he tried to stream pandora at that level and it just refused to work. Which is very important in this time of cloud based music services.

    Guides like this are meant as reference to get you started. Nobody can be 100% certain this will work on 100% of the phones. Some will require lower max setting and others will be able to utilize the lower min settings.
    03-29-2012 05:16 AM
  20. LeslieAnn's Avatar
    What you posted is a very good starting point. I wish I could find the post Blarf made about the governors and clock speeds. It was explained well enough that the new people could comprehend it.
    That post by Blarfie I think is on XDA.
    I think Jerry was mostly responding to the post above his, I could be wrong though.

    Honestly, it's only meant as a starting point*, obviously you can do fine just on this, but if people really want to go beyond this, you could literally write pages on the subject, but this should be more than enough for the casual overclockers that most people are.

    In the post, it doesn't outright say it for the high, but more or less implies you have to find what is highest for your phone, but I admit, I really should make that clear and in bold as it is an important point.

    On lows it does state you have to find what works best for you to get that optimal setting. However, I'm still of the state of mind that you are really pretty much just better off leaving it at 480 for minimum. Any gains messing with the low are going to be small, at best, and the losses can be huge. I tried to get the point across that unless you want to invest that kind of time, just leave it at 480 and be done with it.


    *Hardcore overclockers trying to get everything can obviously trash this whole thing with personal preferences, details and such, and that's fine, like I said, this is a guide and starting point. This subject is always a hot topic, I knew that writing it, which is why I used the words theory and believe a few times just to show, it's not all fact. It wasn't meant as the end-all-be-all guide to it, just clear up a lot of junk floating around.



    Also, in the IHO thread I stated (and it should be repeated here) that 122 not working was likely the OS kernels we were using early on. That info came out back when we were only able to use OS kernels to overclock (Xionia stuff is all OS, at least the stuff that works). It probably started working when we started making our own kernels.
    Dave Begue likes this.
    03-29-2012 06:54 AM
  21. flapjack.fiasco's Avatar
    All this information is great. We've actually gotten a few issues aired out here since yesterday, and that benefits everyone. I know I learned quite a bit from this discussion, and I hope that it prompts others to further investigate the mysteries that still remain.

    It might be nice to pull in some of Dannemand's info from the IHO thread into the OP and get this thread stickied.

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    LeslieAnn likes this.
    03-29-2012 09:36 AM
  22. tdm's Avatar
    Unless you perform those test on each and every kernel, they are irrelevant to anyone not using the same kernel as you are.

    One kernel may be able to go down to 122, while perhaps the stock kernel couldn't? Zefie's original comments were made in the beginning of OV kernel development, so things could easily have changed.
    Yes, the stock kernel had 122. The stock list is: 122800, 245760, 320000, 480000, 600000.

    picasticks etc. added 729600, 748800, 768000, 787200, 806400, 825600, 844800, 864000.

    See arch/arm/mach-msm/acpuclock.c around line 211, for the definition of pll0_960_pll1_245_pll2_1200. Note you ignore the entries with 0 as the first item.
    LeslieAnn and flapjack.fiasco like this.
    03-29-2012 09:37 AM
  23. nixie21's Avatar
    is it good to set a profile for screen off at 320/245?

    Sent from my LG-VM670 using Tapatalk
    03-29-2012 09:54 AM
  24. Dannemand's Avatar
    Unless you perform those test on each and every kernel, they are irrelevant to anyone not using the same kernel as you are.

    One kernel may be able to go down to 122, while perhaps the stock kernel couldn't? Zefie's original comments were made in the beginning of OV kernel development, so things could easily have changed.
    Jerry, I think you were responding to my post just before yours, but I am not quite sure what specifically you are referring to. I was merely adding some info about governors and recommended use of CPU Spy to help guide one's OC settings.

    It's true, everything I have posted on the subject has been in the context of IHO and the kernels you guys have used the last 6-7 months. Studies of CPU settings and governors were one of the first things I did when I came to IHO in Sep-Oct last year because I have a lot of experience in that field.

    I don't know how many of the old kernels are still being used. I always see you and others recommend leaving the old ROMs behind because they are unsupported, and I think it is reasonable to post test results and findings based on IHO without long disclaimers.

    If you disagree with anything I've posted, please let me know. You are one of my absolute heroes here (I've said as much several times) and I certainly don't want to step on your toes in any way.
    flapjack.fiasco likes this.
    03-29-2012 10:58 AM
  25. Dannemand's Avatar
    I would like to point out that that there is hardly anything that I've observed or written (here or in the IHO thread) that contradicts with what I've seen LeslieAnn say (other than the existence of 122, which is not significant in itself, and probably just due to newer kernels since Zefie's days). On the contrary, ever since I started following this forum a year ago, I've found LeslieAnn's writings on the subject to be islands of fact and reason in a sea of noise. Having built overclocked PCs myself for almost 20 years, I recognize that.

    This thread is an excellent contribution in that LeslieAnn lays out a process for determining the right OC settings process being the key word here.

    There are a lot of myths in the area of over/underclocking, partly due to lack of understanding, which leads to this pursuit of "the one perfect setting". There is no such thing, both because each phone's hardware is different, but also because we all use our phones in different ways.

    So ideally, people need to go through this process to determine the right settings for them.

    The classic recommendation of Min=480, Max=two notches down from stable is a great starting point; or a great default for those who (understandably) don't want to go through this process -- although it still requires some work to determine Max. There is nothing wrong with simply sticking to that. But that doesnt make it the best setting. Its simply the best starting point and not a bad place to be if thats where you end up staying.
    flapjack.fiasco and LeslieAnn like this.
    03-29-2012 11:14 AM
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