What is the difference between undervolting and underclocking? What does each do to battery life, performance, etc.
Also, what are the best, stable undervolting and underclocking value for the Rezound? I'm running Neo's Tron rom
gleggie said:
What is the difference between undervolting and underclocking? What does each do to battery life, performance, etc.
Also, what are the best, stable undervolting and underclocking value for the Rezound? I'm running Neo's Tron rom
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Undervolting is lowering the amount of power the processor draws at a certain frequency. Let's say, for example, a processor uses 1025mV at 1.18GHz normally. If you lower the voltage to 975mV for that frequency (using System Tuner or something similar) that's undervolting. If you lower the voltage too much the device will be unstable and reboot.
Underclocking is lowering the top speed of a processor. On our Rezound, the maximum speed of our processor is 1.5GHz stock. If you lower the maximum speed to 1.18GHz that's underclocking. Obviously lowering the maximum speed of the processor will decrease the performance of the device somewhat, depending on how much you lower it and what you're doing. Just getting on Twitter and XDA you might not notice the difference in speed, but during gaming it'll become more prevalent.
There isn't an established "best" amount to undervolt by, as each device is different. One device might be able to undervolt by 50mV with no problems, while another might not be able to handle any undervolting at all. If you're using the latest version of TRON ROM you should already be on Snuzzo's FunkyBean kernel, which has been undervolted by 50mV at every frequency.
Undervolting is also a subjective thing. Some people choose to go with 1.18GHz, while others may choose something higher than that, like 1.35GHz. It all depends on how you use your device and how you want it to perform. I suggest trying out something around 1.24GHz and seeing if it's alright with you. If it's too laggy just raise the speed bit by bit until you're satisfied with it.
I'm sorry for the long winded reply, but I wanted to make sure I covered everything.
Sent from my ADR6425LVW using XDA Premium.
SteveG12543 said:
Undervolting is lowering the amount of power the processor draws at a certain frequency. Let's say, for example, a processor uses 1025mV at 1.18GHz normally. If you lower the voltage to 975mV for that frequency (using System Tuner or something similar) that's undervolting. If you lower the voltage too much the device will be unstable and reboot.
Underclocking is lowering the top speed of a processor. On our Rezound, the maximum speed of our processor is 1.5GHz stock. If you lower the maximum speed to 1.18GHz that's underclocking. Obviously lowering the maximum speed of the processor will decrease the performance of the device somewhat, depending on how much you lower it and what you're doing. Just getting on Twitter and XDA you might not notice the difference in speed, but during gaming it'll become more prevalent.
There isn't an established "best" amount to undervolt by, as each device is different. One device might be able to undervolt by 50mV with no problems, while another might not be able to handle any undervolting at all. If you're using the latest version of TRON ROM you should already be on Snuzzo's FunkyBean kernel, which has been undervolted by 50mV at every frequency.
Undervolting is also a subjective thing. Some people choose to go with 1.18GHz, while others may choose something higher than that, like 1.35GHz. It all depends on how you use your device and how you want it to perform. I suggest trying out something around 1.24GHz and seeing if it's alright with you. If it's too laggy just raise the speed bit by bit until you're satisfied with it.
I'm sorry for the long winded reply, but I wanted to make sure I covered everything.
Sent from my ADR6425LVW using XDA Premium.
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Thanks for the thorough response!
Related
Yesterday I thought I would test my battery life if I left my clock speed at 806 MHz, It lasted over 24 hours with no real speed decrease... I am requesting that a developer makes a kernel that is underclocked to 806 MHz and undervolted as much as possible so we can see how much battery life we can pull out of this thing.
take intersectRavens 800mv (or 925) kernel and underclock via setcpu?
lower than 800mv won't be possible, even 800mv is too low for me, it uses more battery cause data connections is very unstable. 925 gives better battery life for me.
IR kernel supports conservative governor too.. works great for me.
yeah just use set cpu to underclock the device. all these kernels already have the lowest voltages for each cpu frequency. but once again, the lower the voltage, the lower your signal strength, and if you signal strength gets too low, your phone will boost voltage to the radio to try to increase it and it will end up using more power. this is why many prefer the 925mv kernels as opposed to the 800mv ones.
this is my understanding, please correct me if i am wrong.
nellyspageli said:
yeah just use set cpu to underclock the device. all these kernels already have the lowest voltages for each cpu frequency. but once again, the lower the voltage, the lower your signal strength, and if you signal strength gets too low, your phone will boost voltage to the radio to try to increase it and it will end up using more power. this is why many prefer the 925mv kernels as opposed to the 800mv ones.
this is my understanding, please correct me if i am wrong.
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I wasn't sure, that's why I said lowest possible. So I think I'll just do that, but from what you said I'm now wondering if we can OV the radio's voltage from the kernel to fix the 3g/speed problems...
will it work on froyo? i have CM6alpha1
link to the kernal to use and setCPU settings please (including profiles) much appreciated!
Hei, could someone explain something to me really quick?
I'm currently OC'ing 122/787 but as I understand that's not very good battery wise.
I'm just trying to get as much performance as I can in the limits of not affecting battery (at all if possible). I don't really care if I run at 768 or 787 or 806.... the difference is only really seen in benchmarks and maybe zooming in web browser. I don't do gaming that much.... only now and then, and I can do it before gaming if I really want performance. Anyway....
As I understand, there are... "same voltages" for different frequencies and that means different (higher) frequencies have the same impact as lower ones. Right?
I've read around here that doing 480/729 is the most viable as 480 runs at the same voltage as 122 and actually is better because it allows the cpu to idle faster.
729 would be the highest you could go in OC without stepping over the voltage (which means 729 runs at the same voltage as 600).
Can someone confirm this?
Does anyone know which is the actual impact? Like... in hours not % if possible.
I'd try this myself but I use the phone differently each day and I can't really tell...
What's the purpose of overclocking and undervolting. What's the reason for the undervolting?
Sent from my ADR6400L using XDA App
It reduces CPU temperature and the amount of battery needed. It is especially useful when you overclock your CPU as both benefits are seen then.
Undervolting typically increases instability, unless it is also in conjunction with underclocking.
If you overclock, you might add voltage to keep the processor running higher than its rated speed. Similarly, if you drop the clock cycles, you may be able to drop voltage and run a cooler, more power-friendly processor.
I am currently underclocking to 768MHz on stock voltage.
Is that why with the speedtweak on 1.92 with the under volting makes the phone lock up.
Sent from my HTC ThunderBolt using XDA App
Likely. The only time I experienced frequent locks was when I was undervolted extremely. If you're running an overclocked and undervolted simultaneously you increase the odds that the cpu won't have enough juice to run properly.
Virtually every device will tolerate speedtweak's extreme undervolt/overclock to 1.41GHz with complete stability. Most will also remain stable running within stock voltage up to 1.222GHz. I've never been a fan of running with a hard cap on speed. Adjusting governor settings makes more sense. I'm also thinking underclocking and using HTC stock voltage scaling is a waste since the CPU will definitely remain more stable at more extreme undervolting at those speeds. Some kernels will run well with a minimum voltage of 650.
What are the best settings to have you phone's CPU speed set at? I'm looking for both good performance and good battery. Also I am using the default overclocker, what is the best one? Thank you guys for your time.
Sent from my LG-VM670 using XDA Premium App
I use SMARTASS as my CPU speed governor and I set my CPU to 480-748 MHz, seems pretty stable for me.
Sent from my LG-VM670 using xda premium
thaunknownartist said:
What are the best settings to have you phone's CPU speed set at? I'm looking for both good performance and good battery. Also I am using the default overclocker, what is the best one? Thank you guys for your time.
Sent from my LG-VM670 using XDA Premium App
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Overclocking values differ from phone to phone. Test it out with different values and use the one which is stable for you.
This was just discussed in the IHO technical-discussion thread, as a matter of fact.
My phone is stable for most stuff at 806 MHz, but sometimes the camera will cause a freeze/reboot. So I run at a 786 MHz max. Your phone will be different; this has to do with minute physical differences between individual chips.
The thing to keep in mind when overclocking is that the processor in our phone (unlike those of many other phones) does not make use of dynamic voltage scaling. There are only two voltage levels: a lower one if the phone is running at or below (or is it just below? correct me if I'm wrong, guys) 480 MHz, and a higher one if the phone is running above. So below 480 MHz, the system will give the processor a certain amount of voltage (period), and above, the processor will get a certain higher amount of voltage (period).
Because of that, the tests that have been done indicate that 806 MHz is the sweet spot for battery efficiency when the phone is in use--and the closer you get to 806, the better. Thus, I've had the following settings for quite some time:
786 MHz min
786 MHz max
Performance governor
which has treated me pretty well. On a day of light to moderate use, I'd end up with 65-75% battery left (occasionally more like 80%), depending on cell signal where I am et al. And it gives me probably the best performance I'm gonna get out of this phone.
However, I very recently decided to change the minimum to below that 480 MHz threshold and see what a lower voltage when idling would do for my battery life. My current settings are:
320 MHz min (may change to 480)
786 MHz max
Smart*** governor
There is actually a noticeable performance decrease when I first wake the phone up, so I may switch governors as well. In any case, I've had those settings for only one full day now, but for that one day the battery life was noticeably better. I'll post an update when I've had a few more days to test.
As always, it's difficult to quantify battery life in a reliable/rigorous manner (much less a universally applicable one), so YMMV.
Hi there,
I have searched the forum for a suitable answer but couldn't really find one.
after experimenting with different kernels and underclocking I have always wondered what the pro's and con's are for using 100 Mhz as lowest frequency.
thanks
using cm9 latest + neak 2.0.2
eC1990ho said:
Hi there,
I have searched the forum for a suitable answer but couldn't really find one.
after experimenting with different kernels and underclocking I have always wondered what the pro's and con's are for using 100 Mhz as lowest frequency.
thanks
using cm9 latest + neak 2.0.2
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Really 100mhz is useless, it uses the same voltages as 200mhz (so uses same amount of power as 200mhz) and you get a lot less performance. Also, from what it have seen I can be unstable for quite a few people. I really can't see any pros to 100mhz. I would recommend you don't use it. So you are using the same amount of energy for less performance and less stability. Hope this helps you
will give you 10 to 30 mins of additional battery life if you configure it properly.
Try siyah kernel and follow the guides in general section
I have a question related to this topic. I know that overclocking can reduce CPU life, but what effect does underclocking? Same CPU life? Maybe it increases the battery life but reduces the CPU life due to CPU not working in the native way?
Haven't found an answer for this yet. It would be useful to know about it since replacing a battery is way more easier and cheaper than anything you could do if CPU dies.
Edit: I'm refering to general underclocking (max and min frequencies, not only the min frequency).
GNRS said:
I have a question related to this topic. I know that overclocking can reduce CPU life, but what effect does underclocking? Same CPU life? Maybe it increases the battery life but reduces the CPU life due to CPU not working in the native way?
Haven't found an answer for this yet. It would be useful to know about it since replacing a battery is way more easier and cheaper than anything you could do if CPU dies.
Edit: I'm refering to general underclocking (max and min frequencies, not only the min frequency).
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underclocking wont affect the life of your cpu. the least underclock value will only be used when your mobile is almost idle or doing low intensity tasks, it will switch to higher frequency as needed by the task.