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Undervolting - I am very confused!

I am on CM7 (n72) with faux's latest 0.2.9 uv kernel, and am undervolted all the way down to 10 mv each on the 389 and 503 frequencies with no performance changes. I have tried setting it with both setcpu and pimpmycpu. I know there can't be a way for my phone to be working at those levels so what am I doing wrong? Am I missing something?
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If you lowered the voltages to -10 then you have not lower to aggressive. If you lower the volts to much device will not boot. I am at -50 across all values. Lower the volts is supposedly to improve battery (life) performance not speed performance.

To be quite honest with the questions the OP is asking he shouldn't be messing with an UV kernel.

Ok, I believe the kernel has a built in minimum mv that it will run at, regardless of how low you set the values in setcpu. Im certain that faux posted what that low value was once when someone else was bragging about undervolting by -250...you aren't really undervolting that low. However, some of our phones cant even handle that minimum low voltage, so consider yourself lucky.
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mmapcpro said:
Ok, I believe the kernel has a built in minimum mv that it will run at, regardless of how low you set the values in setcpu. Im certain that faux posted what that low value was once when someone else was bragging about undervolting by -250...you aren't really undervolting that low. However, some of our phones cant even handle that minimum low voltage, so consider yourself lucky.
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Thank you that's what I was wondering about! Sorry if I didn't phrase my question correctly, I meant the voltages were set at 10 mv, not lowered by 10
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I ran into the same problems. In another thread, faux123 stated that the way tegra works, each adjacent frequency level should only differ by ~ 100mV. so if you started with 1000mhz @ 1000 mV, then the next frequency will be 800mhz @ 900mV (just an example). so pretty much it all depends on how low of a voltage your top frequency can run on. if your voltage difference between 2 adjacent frequencies is larger than ~100mV, then it means nothing.
again, I gathered this info from faux. I have no sold knowledge whatsoever

prettyboy85712 said:
To be quite honest with the questions the OP is asking he shouldn't be messing with an UV kernel.
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We all have to start from somewhere, be nice. It sounded like he misspoke.

Kernal voltages?

I'm sorry for the noob question but I really don't understand voltage terms and what's it for and how it work I was wandering if anyone could explain it to me?
In the past I would use set CPU and create a few profiles and would be done with it but I been reading on the forums about setting voltages higher and lower for better performance.
Currently i'm on eagles blood 2.3.5 ROM, trinity t15 (fun) kernel.
Any help would be much appreciated.
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Don't know what it does don't use it
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ritthyhang said:
I'm sorry for the noob question but I really don't understand voltage terms and what's it for and how it work I was wandering if anyone could explain it to me?
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It's to save power and get better battery life. You lower the amount of power the chip gets at various clockspeeds until it starts not working correctly, then back up to a voltage at which the chip is stable at that clockspeed. Some chips can handle lower voltages than others while still working correctly.
Overclocking = get better performance
Undervolting = get better battery life
Both can lead to phone instability if you set the values to extremes.

Thank you for the info
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lannister80 said:
It's to save power and get better battery life. You lower the amount of power the chip gets at various clockspeeds until it starts not working correctly, then back up to a voltage at which the chip is stable at that clockspeed. Some chips can handle lower voltages than others while still working correctly.
Overclocking = get better performance
Undervolting = get better battery life
Both can lead to phone instability if you set the values to extremes.
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Click to collapse
So lemme ask this how do I undervolt and what voltage is safe to undervolt?
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ritthyhang said:
So lemme ask this how do I undervolt and what voltage is safe to undervolt?
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It all depends on the kernel your using and if it supports UV, it should say if it does in the name of the kernel tho(just look for uv ) Setcpu 2.2.4 will allow you to change voltages only if your kernel/rom support it.
you can safely undervolt -50 -75 at most all the way up to 1.0ghz-1.1ghz i wouldn't undervolt past that.

d12unk13astard said:
It all depends on the kernel your using and if it supports UV, it should say if it does in the name of the kernel tho(just look for uv ) Setcpu 2.2.4 will allow you to change voltages only if your kernel/rom support it.
you can safely undervolt -50 -75 at most all the way up to 1.0ghz-1.1ghz i wouldn't undervolt past that.
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So what your saying is I can use setcpu to change the voltage?I just recently changed kernels I saw that option available but I didn't understand how to use it.under voltages it shows all the GHz underneath it it shows 0.From here what do I do?, do I go too each GHz profile and -50 from all of it?
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Voltage control on ICS?

Is there an app that will work to control voltage on ICS yet?
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Nstools
Link - http://forum.xda-developers.com/showthread.php?t=1333696
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ROM Toolbox Pro also allows you too modify these settings.

Or setcpu
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Do these require specific kernels to work?
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Yes , not all kernels allow change voltages
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Voltage adjustment is not really necessary, unless you are increasing voltages for overclocking.
NStools is a Nexus user favorite, powerful, and free.

Braneless said:
Voltage adjustment is not really necessary, unless you are increasing voltages for overclocking.
NStools is a Nexus user favorite, powerful, and free.
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Voltage adjustment is necessary when UVing so you can save battery duh??? lol
Even when overclocking.

XxLostSoulxX said:
Voltage adjustment is necessary when UVing so you can save battery duh??? lol
Even when overclocking.
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Click to collapse
Uhh, no. I suggest you read up on the findings/observations documented by multiple kernel developers and bedalus's kernel testing posted here. UV has no effect on power consumption.

Read first post http://forum.xda-developers.com/showthread.php?t=1448900
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Braneless said:
Uhh, no. I suggest you read up on the findings/observations documented by multiple kernel developers and bedalus's kernel testing posted here. UV has no effect on power consumption.
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Well I tested it on my friends nexus s 4g and my epic 4g and with a lot of UVing. Lemme further explain.
Okay when you UV it just uses less amount of voltage on that frequency so in essence you save battery because not as much voltage is being used. Now however if you UV by a lot like -100mV and higher the phone will lagg a bit. If you overvolt your pushing more voltage to the phone which is more power being used.
I just tested my phone freqs. Used were 100,200,400,600,800,1000 And all were UVed by -100mV and playing games and using lower freqs it will lagg. When I didn't UV at all it never lagged.
Not to mention BTW I was @ 88% before and it only took me 2 mins to post this and now I'm at 86% with no UV at all. And last post before this I took me same time with UVed I went from 95% to 95% lol.
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XxLostSoulxX said:
Voltage adjustment is necessary when UVing so you can save battery duh??? lol
Even when overclocking.
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Click to collapse
Not according to my testing.
kernels ; battery ; ROM ; gov/sched
Now with summaries in the first posts. Convenient for XDA app users!

bedalus said:
Not according to my testing.
kernels ; battery ; ROM ; gov/sched
Now with summaries in the first posts. Convenient for XDA app users!
Click to expand...
Click to collapse
Well I can say every phone is a tad bit diff. But for whatever reason no matter who's phone when I UV if the phone handles it it. It saves me battery I want you to test this and see.
Run whatever scheduler and say performance run 100 MHz by -200mV like and 200 Mhz by -150mV and so forth. Play GtA 3 and watch when UVed it laggs and when Not it laggs stillbut not as bad. I mean hell even 1.5GHz no UV I still lagg haha
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Thanks guys! Ill check on this some more when I get home.
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SetCPU

I know that if you OC/UV incorrectly, it can cause stability issues. But I was wondering does it cause any damage to the phones hardware like battery, etc? And like how can you tell when SETCPU is causing problems?
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Well if you OC to high numbers your just stressing the cpu more.Knowing when you have issues is simple getting random reboots,phone getting too hot etcc.
It differs for every phone but undervolting -25 for each voltages works well.
Personally I really don't see the point overclocking to high levels like 1.4 ghz etc,Is up to individual I guess.
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daxecutioner24 said:
Well if you OC to high numbers your just stressing the cpu more.Knowing when you have issues is simple getting random reboots,phone getting too hot etcc.
It differs for every phone but undervolting -25 for each voltages works well.
Personally I really don't see the point overclocking to high levels like 1.4 ghz etc,Is up to individual I guess.
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Yeah I have been wondering what's the point of OC to 1.4? Does it make that big of a difference in the 4g speed? And cpu speed?
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Honestly, there really is no point other than for benchmarks. I, like mt3g, actually underclock the phone to something like 750-760mhz; it runs beautifully smooth.
Other than that, if you game a lot and want to maximize FPS, then overclocking would do that for you.
Doesn't have anything to do with 4g speed afaik. That's entirely reception.

Yeah 4g is about reception and tmobile simply.
I mean I had single core devices like MT4g ,SGS 4g for the most part on a day to day basis transitions to transitions theres not much diffirence in terms of speed. Now for FPS and a few other games you need that dual core.Point is there"s no need to OC a dual core phone!
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I have had mine OC'd to 1.1 ghz with some undervolts. It is very stable , 10-12 hr battery with medium to heavy use , and ofcourse fast. Took a while to find the best settings.

When I have SetCPU set to 1015 megahertz, that's the same as stock voltage, isn't it?

NekoNyapii said:
When I have SetCPU set to 1015 megahertz, that's the same as stock voltage, isn't it?
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What does CPU speed have to do with voltage?

theking_13 said:
What does CPU speed have to do with voltage?
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I meant the same as stock speed.
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setcpu phone overclocking
Changes you might see are battery life but not that much unless you so how mess with voltage. Like other have said you know it effecting stability when its overheating, shutting down randomly, exiting program randomly.

Nexus 5 Overclocking

OK, first of all I'd like to apologise for all the questions I keep posting. Im quite a noob with android, and coming from an iPhone, it's been a big leap. I'm just overwhelmed by the android system and how open it is! But I do all this cool stuff to my android like everyone else, although I don't wanna ruin a £350 phone by doing something stupid without guidance! (I'm just a big kid really! ) Which is why I keep posting questions, because it's hard to Google/Search XDA for this stuff...
Whenever I search XDA for 'Nexus 5 Overclocking' all I get is ROM threads, so this will be a thread for everything [under][over]clocking! Share your most effective results, and ask the pros questions!
I'll start it off...
I've Underclocked before, but now I wanna Terry out some heavy emulators (dolphin emulator, Nintendo 64 emulator ect.) But I don't think my phone is powerful enough to run these games full speed underclocked... I want to OVERclock it now, so which apps do I need to achieve this, how do I do it, and what are the most effective values for it?
Thanks,
Pro_Vickers.
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The kernel defines whether or not you can overclock.
There is no real need to in the nexus 5 though.
If it is choppy at 2.3ghz then there is something wrong with the emulator.
In context I play final fantasy 9 on the psx emulator fpse using opengl graphics (which is limited to single core) and still get a constant 60fps
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ProVickers said:
I want to OVERclock it now, so which apps do I need to achieve this, how do I do it, and what are the most effective values for it?
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Hi,
First you need a kernel with overclock (Franciscofranco, Trinity, ElementalX, etc...).
For the apps Franciscofranco have its own app (Francsico Kernel Updater-> FKU) and Trinity kernel also (Trinity Kernel Toolbox-> TKT), all available on the Play Store.
You can use a "generic" app like Trickster Mod, Play store too.
With the apps you choose your max CPU freq and it's done...
For overclocking there is no "most effective value" it depends of the voltage and what your CPU can handle. 2,4/2,5 Ghz seems reasonable (with some kernels you can go above like 2,8 Ghz).
Try a "safe" overclock first like 2,4/2,5 Ghz, and don't set the CPU freq "at boot" to avoid any problem like bootloop in case your CPU can't handle these freqs.
Maybe you'll need to raise a bit the voltage for these CP freqs, it depends of your CPU binning.
You can apply your settings at boot via the app when you are sure that all is stable (so after a few days of test with your use).
In any case you'll need to test in different situations to see if all is fine (hard and normal use)...

Alex240188 said:
The kernel defines whether or not you can overclock.
There is no real need to in the nexus 5 though.
If it is choppy at 2.3ghz then there is something wrong with the emulator.
In context I play final fantasy 9 on the psx emulator fpse using opengl graphics (which is limited to single core) and still get a constant 60fps
Sent from my Nexus 5 using xda app-developers app
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I've Underclocked and it's choppy, but I know it's not the emulators fault because of the reviews, and I've played with it before I Underclocked... The problem is, I forgot how I Underclocked, so can you tell me how I clock it back to stock GHz?
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P.S
I have Franco kernel so clocking shouldn't be a problem should it? Also can I use trickster mod for it? Thanks

viking37 said:
Hi,
First you need a kernel with overclock (Franciscofranco, Trinity, ElementalX, etc...).
For the apps Francisco have its own app (Francsico Kernel Updater-> FKU) and Trinity kernel also (Trinity Kernel Toolbox-> TKT), all available on the Play Store.
You can use a "generic" app like Trickster Mod, Play store too.
For overclocking there is no "most effective value" it depends of the voltage and what your CPU can handle. 2,4/2,5 Ghz seems reasonable (with some kernels you can go above like 2,8 Ghz).
Try a "safe" overclock first like 2,4/2,5 Ghz, and don't set the CPU freq "at boot" to avoid any problem like bootloop in case your CPU can't handle thes freqs.
Maybe you'll need to raise a bit the voltage for these CP freqs.
In any case you'll need to test in different situations to see if all is fine...
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Click to collapse
Hi,
I've Undervolted -75, so should overvolt or set it back to stock values so I can safely try out 2.5Ghz?
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ProVickers said:
P.S
I have Franco kernel so clocking shouldn't be a problem should it? Also can I use trickster mod for it? Thanks
Click to expand...
Click to collapse
Re,
Yes you can overclock with Francisco's kernel and yes you can use Trickster mod...
ProVickers said:
Hi,
I've Undervolted -75, so should overvolt or set it back to stock values so I can safely try out 2.5Ghz?
Click to expand...
Click to collapse
Try with your undervolt...
But in first I would try with the original voltage, not necessary overvolting...
Try and see, only you can know if it will be safe or not...

viking37 said:
Re,
Yes you can overclock with Francisco's kernel and yes you can use Trickster mod...
Try with your undervolt...
But in first I would try with the original voltage, not necessary overvolting...
Try and see, only you can know if it will be safe or not...
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Click to collapse
All I can see in FKU is Max CPU frequency (960MHz), min (422MHz) and GPU frequency (320MHz) under GPU control... What do I tinker with to get it to 2.4GHz?
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ProVickers said:
All I can see in FKU is Max CPU frequency (960MHz), min (422MHz) and GPU frequency (320MHz) under GPU control... What do I tinker with to get it to 2.4GHz?
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Click to collapse
Re,
Max CPU at 960 Mhz
You only see this CPU freq? Maybe your phone is actually to hot and the CPU freq is decreased?
"Click" on Max CPU freq then scroll down to see all the CPU freqs...

viking37 said:
Re,
Max CPU at 960 Mhz
You only see this CPU freq? Maybe your phone is actually to hot and the CPU freq is decreased?
"Click" on Max CPU freq then scroll down to see all the CPU freqs...
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Click to collapse
Sorry, I mean that's what it's set at, I can see all of the frequencies, but which ones do I set?
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ProVickers said:
Sorry, I mean that's what it's set at, I can see all of the frequencies, but which ones do I set?
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Ok...
Hum... you choose the one you want, you want to overclock so overclock. The stock CPU freq is 2,26 Ghz so if you go above this freq you overclock...
Maybe it's why "But I don't think my phone is powerful enough to run these games", like you said, if your max CPU freq was at 960 Mhz...?

Default the stock max freq will be 2260 MHz or 2.26ghz depending on how it's displayed.
I'd leave your undervolt as it is for now and just increase the max frequency and see if it becomes smooth for what you need
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viking37 said:
Ok...
Hum... you choose the one you want, you want to overclock so overclock. The stock CPU freq is 2,26 Ghz so if you go above this freq you overclock...
Maybe it's why "But I don't think my phone is powerful enough to run these games", like you said, if your max CPU freq was at 960 Mhz...?
Click to expand...
Click to collapse
Alex240188 said:
Default the stock max freq will be 2260 MHz or 2.26ghz depending on how it's displayed.
I'd leave your undervolt as it is for now and just increase the max frequency and see if it becomes smooth for what you need
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I know that my phone is fast enough (obviously, it's a nexus 5 beast!), and I know that I lowered my CPU frequencies, but it's just that I forgot what the defaults were, and how to change it. I know now, thanks you guys! P.S should I change my min frequency or is that fine?
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ProVickers said:
I know that my phone is fast enough (obviously, it's a nexus 5 beast!), and I know that I lowered my CPU frequencies, but it's just that I forgot what the defaults were, and how to change it. I know now, thanks you guys! P.S should I change my min frequency or is that fine?
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Click to collapse
Ah ok, you should have explained it at the beginning... , you're welcome
Stock min CPU freq is 300 Mhz..., not sure you'll see any gain to set it to 422 Mhz...
Set it again at 300 Mhz and see...
In any case if sometimes you have a doubt about some stock settings, disable the set on boot option and reboot, all the stocks settings will go back. Or in FKU, App settings then clear data for FKU.