Database Info

Undervolting FAQ

I read a lot about undervolting on here and i think i have an idea about what it does but i may be way off, and im sure each device is different. in pimp my cpu there are multiple options, and while this sounds newbish i think this should be explained to folks in some more detail.
this is what im assuming.
undervolting allows for less power consumption.
UV on higher OC levels controls power spikes to the CPU?
what is a safe level to UV and at what frequencies specific to the G2x
i am reading up on this, to get a better idea. http://www.android.net/forum/android-rooting/58117-droid-x-guide-undervolting-guide.html

Here's my understanding of the whole undervolting thing..
In order to maintain stable operation across devices with varying production quality (not all chips are created equal), manufactures use voltage levels higher than necessary for most devices. They cater to the least common denominator. But most phones will still operate reliably at a lower voltage. By undervolting you can extend your battery life and ward off chip killing heat. This all becomes even more important when overclocking. When you overclock your device you increase the power usages (those extra megahertz aren't without cost). This increases both the drain on your battery and the heat produced by your CPU. Undervolting helps to offset both issues.
As for the proper undervolting levels...that will vary with the tolerance of each individual device. But I'm sure someone can provide some general guidelines...sorry I haven't undervolted the g2x yet and don't want to steer you wrong.
Hope this helped...

Good info. I dropped mine .25 on each higher level. So ill see how it goes
G2x with CM7 and faux kernel

what confuses me on this topic is the "it's different for each device" phrase that I keep reading. Is this in reference to the rom/kernel that is being used or is it specific to apps installed/how the phone is used.. or is it a combo of both?
It's confusing me because its seems that OC/UV is hardware specific and each phone has the same hardware. So I don't quite get this "it's different for each device" thing..

schmit said:
It's confusing me because its seems that OC/UV is hardware specific and each phone has the same hardware.
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Each phone doesn't have the same hardware....for example, G2X has an nvidia tegra 2 and the nexus s has a hummingbird.

i think you mean this.
cybereclipse said:
Each phone doesn't have the same hardware....for example, G2X has an nvidia tegra 2 and the nexus s has a hummingbird.
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yes all g2x's have a tegra 2 chip.
But production does not always produce the same tolerances for all the chips.
ussually(with the quality control apparently given to the g2x who knows) but ussually all chips are tested and every chip that is in a g2x will perform reliably at 1ghz as it is specified and sold at.
some of these will run reliably at 1500 or better while some will not go over 1100 without starting to get unreliable.
example is the droid 1 was sold at 550 mhz. they did an update that upped it to 600mhz so they knew all chips were tested to be ok at that threshold. Mine would run at 1200 reliably no overheating(except running flash) no reboots.
with 2 different kernels. there was another kernel that they messed with the voltages so that i would get constant reboots even at 700mhz.
some droids would not run over 700 without experiencing problems.
So yes the tegra 2 chips is the same but the abilities of it can be different. they are guarenteed to run at the speed they are sold at but most will function at a much higher speed without problems while some will not.
oh just thought of a great example. the AMD tri-core processors.
those are quadcores where 1 of the cores did not pass the tests but the other 3 did so instead of scrapping the entire chip they turned off the bad processor and sold it as a tricore. there are motherboards out there that allow this core to be turned back on and many have done this and it works just fine. its just that core didnt pass whatever minimum they set on it even though it was perfectally functional they determined that if it got to this temp or didnt run at this speed(over what it was sold at) it didnt pass.
So while this kernel at this voltage may run fine on your phone it may caused reboots or lock ups on others.
hope this makes some sense.

eagle1967 said:
yes all g2x's have a tegra 2 chip.
But production does not always produce the same tolerances for all the chips.
ussually(with the quality control apparently given to the g2x who knows) but ussually all chips are tested and every chip that is in a g2x will perform reliably at 1ghz as it is specified and sold at.
some of these will run reliably at 1500 or better while some will not go over 1100 without starting to get unreliable.
example is the droid 1 was sold at 550 mhz. they did an update that upped it to 600mhz so they knew all chips were tested to be ok at that threshold. Mine would run at 1200 reliably no overheating(except running flash) no reboots.
with 2 different kernels. there was another kernel that they messed with the voltages so that i would get constant reboots even at 700mhz.
some droids would not run over 700 without experiencing problems.
So yes the tegra 2 chips is the same but the abilities of it can be different. they are guarenteed to run at the speed they are sold at but most will function at a much higher speed without problems while some will not.
oh just thought of a great example. the AMD tri-core processors.
those are quadcores where 1 of the cores did not pass the tests but the other 3 did so instead of scrapping the entire chip they turned off the bad processor and sold it as a tricore. there are motherboards out there that allow this core to be turned back on and many have done this and it works just fine. its just that core didnt pass whatever minimum they set on it even though it was perfectally functional they determined that if it got to this temp or didnt run at this speed(over what it was sold at) it didnt pass.
So while this kernel at this voltage may run fine on your phone it may caused reboots or lock ups on others.
hope this makes some sense.
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Nice...that was much better than my explanation.

cybereclipse said:
Each phone doesn't have the same hardware....for example, G2X has an nvidia tegra 2 and the nexus s has a hummingbird.
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lol. dude, I'm in the g2x forum.. not the "whatever phone ya wanna talk about" forum. I was referring to the g2x's having the same hardware, lol.
Thanks to the other guy for the awesome explanation

What are the dangers of an overclocked CPU/ undervolted kernel?

Please excuse me for my ignorance, but I don't know much about these kinds of topics.
I wanted to know if anybody could be kind enough to explain the dangers and negatives of an overclocked CPU and an undervolted kernel?
I know their benefits because of some research I did, but I could never find a concrete answer explaining the negatives and dangers.
I've heard some horror stories of overheating handsets that get so hot that internal components fry, heard about damaged radios that need to be replaced, and loss of signal. But I'm not entirely sure if those instances are correlation instead of causation.
Any insight would be greatly appreciated. Thank you!
-Chris
Sent from my HTC Sensation 4G using XDA App

The general issue that applies to both modifications is that you are using the chips outside their specifications. Their whole behavior might no longer be as expected.
This is usually happening at such low level and in a so small range that it doesn't affect normal use.
Overclocking will definitely produce more heat. That's why people that overclock pcs to insane levels use non-standard cooling like dry ice or even liquid nitrogen.
As you can't change the way your phone will transport heat, there's only very limited room for overclocking.
The phone is designed to switch itself off if it gets too hot, however this is not something one should rely on.
Not sure about any specific risks of undervolting, but the general issues will definitely apply. Noone can guarantee for stuff to work as expected when you run components outside the specifications, as they were tested to run safe only inside the specs as supplied by the manufacturer.

It can cause permanent CPU damage which can lead to you bricking your phone, but the chances of that aren't that great. Usually if you undervolt too much, your phone will just reboot.

Stability is the biggest issue. It can put the components too far out of their comfort zone.

Unstable, unexpected behaviour and/or (in very strange cases drastically) reduced life expactancy. However, if you do undervolt your cpu, the only/main issue becomes unstable.
In my experience (lot of pc overclocking), you will notice when your material can't keep up with the settings and if you change it (back), no problems will occur.

aNYthing24 said:
It can cause permanent CPU damage which can lead to you bricking your phone, but the chances of that aren't that great. Usually if you undervolt too much, your phone will just reboot.
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So would you say it's worth the risk to flash a ROM that has an overclocked CPU and undervolted kernel? I'm so scared to damage my device
Sent from my HTC Sensation 4G using XDA App

LPChris47 said:
So would you say it's worth the risk to flash a ROM that has an overclocked CPU and undervolted kernel? I'm so scared to damage my device
Sent from my HTC Sensation 4G using XDA App
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Yes I would, in a way the lower voltage cancels out the higher voltage, and even produces less heat overall. There are no dangers of undervolting AFAIK, saving battery is good, although if you set the volt extremely low the phone will freeze up. Devs put the volt at a good level but most of the time you can lower it by a notch or increase it for no reason. If this phone ever gets 2GHz clock that would be a danger to run at, because the voltage would be insane.

[Q] Overclocking cm7 to 1600 Mhz

So overclocking cm7 to 1600 doesnt work and causes boot loops, i have been trying to get a kernel that would do it and i cant find one.
anyone know any kernels that work?

Only kernal for cm7 is the one that is with it no other kernals are compatible as for 1600 some phones run fine at 1600 others don't just depends on your CPU in your phone
Sent from my SGH-I997 using xda premium

^^^ what he said ^^^
my cappy was maginally stable @ 1300 within a very narrow voltage range. my infuse runs 100% @ 1664 with a ton of uv untill i turn on gps and everything starts to get warm. every cpu is different.
most infuses seem to be a higher test cpu than galaxy s phones though. you may be able to run at 1500 or better if you take a lot of time and figure out what the cpu likes and doesnt like. remember heat, uv and rapid voltage change can all cause instability so too much uv can cause problems as well as too little! to get maximum speed you may want keep the top few freq's at the same voltage (not the same uv but the same actual voltage) and have zero uv on the low freq's. it can be a pain to figure it all out but when you see the benchmarks you may think it was worth it.

ok well i kinda messed around with the overclocking built in and was messing with the type of governors and userspace seems to support over clocking on 1600.
really weird but my phone hasnt done the boot loop yet.
but thanks for your guy's help.

I set mine at 1600 last night via SetCPU. After 5 min it got hot and started boot looping. Its running good at 1200 now. I'm gonna bump it up little by little.
Good info, nice to know its "normal".

Honestly, the performance of CM7 outperforms all the other ROMS even running at 1.2GHz (IMO). I really don't see much of a performance increase by stepping up the clock speed, just a decrease in battery life, so it's not worth it to me.

ive talked to many people about this and most can only run at 1.4ghz even though 1.6ghz was stable in froyo. alot of people repeat "it depends on your specific chipset" but i dont buy that cop out. i think theres something wrong with the 1.6ghz setting in cm7.

AnTuTu Benchmarks

I have the highest score listed at 3300. What I'm asking is for people to start downloading AnTuTu Benchmark and running benchmarks while overclocked at 1.152 GHz, see if the score reaches over mine. I want do some research about our phones, but the more scores that are in, the easier and faster ill be able to compile my findings, and come up with something to further increase performance.
sent from my SGH-T839 (Sidekick 4G) running Glorious Overdose V3.0.3.

Benchmarks are bull****. Each value will come up differently depending on what is going on in the background and how Android chose to throttle the CPU while the benchmark was running...
Beyond that...
Overclocking this device is a known source of instability and most devices will crash under heavy load.
Also, I expect the heat will eventually cause issues when using GPS.
Any device is only as good as the weakest link and you are not increasing the speed of the memory, GPU, or the busses on the board.
What you are doing is increasing the heat inside the case above what the heatsinks are designed to handle and causing timing/sync issues.
There have been times in the past that a manufacturer saved money by producing a large amount of one chip and used it in many devices. In that kind of situation, the chip was sometimes "underclocked" and put in budget devices. I can assure you that is not the case with the Sidekick 4g.
Overclocking is an interesting idea in a large PC because there is plenty of room and accessories available. This device is not a PC.

Sorry, didn't see your reply sooner, been busy with the ROM and general life crap. But yes, too fast and you lag, but with the right overclock, you won't get too hot, but a notice a fair amount of increase. Though yes, I only overclock when need be due to increased battery drain. Regardless, I'm doing limit testing for stability purposes, speed purposes, and because I may attempt at one point to see what I can do about coworking 2.3 at the very least before switching over to the G2. After college starts, I won't be on here much at all.
sent from my SGH-T839 (Sidekick 4G) running Glorious Overdose V3.0.3.

[Q] Overclocking but no Exploding

Hi XDA Community. I use Trinity Kernel by Morfic and i was wondering if it is okay to have an Overclocked Nexus 5 and use the phone at a regular basis like a normal stock clock Nexus. I don't want My phone to just randomly explode because of overclocking it. One of the features the kernel has as said at his/her XDA thread is "Up to 2726MHz (higher clocks will vary from device to device)". Is that frequency trustworthy when just using the phone normally or is that a benchmark frequency?

MaLing15 said:
Hi XDA Community. I use Trinity Kernel by Morfic and i was wondering if it is okay to have an Overclocked Nexus 5 and use the phone at a regular basis like a normal stock clock Nexus. I don't want My phone to just randomly explode because of overclocking it. One of the features the kernel has as said at his/her XDA thread is "Up to 2726MHz (higher clocks will vary from device to device)". Is that frequency trustworthy when just using the phone normally or is that a benchmark frequency?
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Don't overclock that high. 2419MHz at most. Overclocking too high will cause more heat and throttle earlier, only useful for a short benchmark such as HWBot Prime or Quadrant (Antutu takes longer and will overheat by the time it finishes). Trinity also supports up to 3014MHz, OP hasn't been updated.

MaLing15 said:
Hi XDA Community. I use Trinity Kernel by Morfic and i was wondering if it is okay to have an Overclocked Nexus 5 and use the phone at a regular basis like a normal stock clock Nexus. I don't want My phone to just randomly explode because of overclocking it. One of the features the kernel has as said at his/her XDA thread is "Up to 2726MHz (higher clocks will vary from device to device)". Is that frequency trustworthy when just using the phone normally or is that a benchmark frequency?
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You don't want to push the phone too much I think the Nexus 5 runs at 2.3 GHz. 2.7 MAY not be too bad but honestly, the phone runs pretty smooth as is. What benefits are you looking for from overclocking?

Thanks guys for sharing your knowledge. You know.. To get the MOST out of the Phone while at the same time being Safe.

if you really wanted, the phone won't explode if you run it at 3015mhz either. the worst that will happen is that your phone won't be able to run that high, and will freeze and reboot.
and don't listen to all.. run your phone how YOU like. yes, it'll cause a little(not much) more heat, and will throttle a little earlier, but that's why people like me disable throttle, so that's a non issue. I run my phone at high CPU speeds all the time, and use 2880mhz high/300mhz low quite often. just because I feel like it, no other reason.
oh, I run trinity as well, and do all of Trinity's testing

MaLing15 said:
Thanks guys for sharing your knowledge. You know.. To get the MOST out of the Phone while at the same time being Safe.
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It's just what @jsgraphicart said. You're not really getting more out of your phone by overclocking. It's not going to run smoother, and most games don't lag anyway so they probably won't run better. I think most people just do it for benchmarks or just to check if it can run on a certain clockspeed.
Also what @simms22 said. You can do it if you want to, but simply because you want to because as far as I know there aren't really any benefits.

Back in my Palm Pre days, we used to overclock that thing to 1GHz. The default setting was 500MHz. I think it was even pushed to 1.2GHz. And it ran fine. But back then, you could tell the difference between a little lag at 500MHz and smoothness at 1GHz. With this phone and how Android has gotten smoother with every update, it's kind of hard to see any difference when overclocking. It will be smooth regardless.

oh, benefits, not really. a little more speed, yes. bit I would never call it a benefit, unless the speed difference was drastic, and its not.

As mentioned, overclocking the CPU can actually turn out to run slower because of aggressive thermal throttling. You could disable or extend the thermal throttling, but 2.3Ghz is already plenty fast for today's mobile software so you won't notice any difference in day to day usage.

bblzd said:
As mentioned, overclocking the CPU can actually turn out to run slower because of aggressive thermal throttling. You could disable or extend the thermal throttling, but 2.3Ghz is already plenty fast for today's mobile software so you won't notice any difference in day to day usage.
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Even if you run your phone at 2880MHz/3014MHz/whatever with thermal throttle off, you can't really do anything too intensive as it'll hit 105C and shutoff lol

Lethargy said:
Even if you run your phone at 2880MHz/3014MHz/whatever with thermal throttle off, you can't really do anything too intensive as it'll hit 105C and shutoff lol
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actually, no, youre wrong. when you run your phone at 2880/300 or 3014/300, you phone will hardly scale up that high, sometimes it will. you wont see any real difference between those high cpu speeds and running it at 2265/300. and battery will be similar. the difference will be if you run it at 2880/2880 or 3014/3014. now i run my phone at 2880/300 very often, and you know i disable thermal throttle. yet, i see no difference in temperatures, except if im doing something thats very cpu intensive.

simms22 said:
actually, no, youre wrong. when you run your phone at 2880/300 or 3014/300, you phone will hardly scale up that high, sometimes it will. you wont see any real difference between those high cpu speeds and running it at 2265/300. and battery will be similar. the difference will be if you run it at 2880/2880 or 3014/3014. now i run my phone at 2880/300 very often, and you know i disable thermal throttle. yet, i see no difference in temperatures, except if im doing something thats very cpu intensive.
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Ah true. But still, a bit easier to hit it if doing something intensive Not to mention it may be a little unstable on some devices

Lethargy said:
Ah true. But still, a bit easier to hit it if doing something intensive Not to mention it may be a little unstable on some devices
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on some devices??? on most devices! anyways, stability is overrated

LOL...no explosions on XDA allowed!