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
Related
Hello Xda.
I made a quick search here and didnt come up with any answers so heres my question.
Do the processors in the myTouch 3G/G1 run dynamically? Meaning they are not clocked at their rated 528mhz at all times?
Ive seen an overclock utility for the G1 and wonder if this is needed for the myTouch also to run at its rated speed?
I appologize if this has been adressed here but i cannot find a definite answer.
same speed all the time
Thx.
Does that apply for both models or just the myTouch 3G?
think it apply for any arm based device I've ever heard of
reason
not sure maybe changing the Hz require too much power for it to pay off
maybe it cause instablity and inresponsive devices
maybe the ability to adjust hz on the fly require extre hardware and software
and it would be too expensive....
Well..there is an app(i believe mostly used by rooted G1 owners)that overclocks
the cpu from an apparent 300'ish mhz to the full rated 528mhz.
The impression i get is that the phone underclocks the processor while using basic functions to save on battery life?..
not the phone the phone manufactors set the default Hz of their device
one reason could be the save batt
another could be they don't have the propper air flow and cooling on the chip
and running it on the Hz the cpu was made for would damage the device
I have a nokia n800. it uses an arm processor running at 400mhz, but not all the time. Only when is required. the o. s. manages this. I think it is related to the o. s. only.
FYI I had minor overheating issues (phone just felt hot to the touch but everything was working fine) with my G1. One day I peeled the piece of fabric off that covers the inside of the speaker hole on the back of the phone, now it stays cool always. Maybe with this fabric removed the phone will run at full speed but stay cool.
Any hint what the software to make this run full speed is called? Is it in the market if you have JF 1.51 firmware? (I do.) I can try it and report back if someone can tell me what it's called.
Rudegar said:
not the phone the phone manufactors set the default Hz of their device
one reason could be the save batt
another could be they don't have the propper air flow and cooling on the chip
and running it on the Hz the cpu was made for would damage the device
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I believe the G1 was underclocked due to its horrible battery life But I believe the MT3G runs at the 528 all the time..
So I have a few apps... Voltage Control, SetCPU, No-Frills CPU... but I've honestly been a bit weary to use them. I want the best battery life since I'm a heavy user, but I also don't want to overclock/set voltage to a point where I'll screw up my phone. I'll admit that I'm a novice user when it comes to voltage/overclocking, but not when it comes to ROMs, kernels, bootloaders, etc. I work with those all the time, but really trying to get the most out of the battery and CPU.
There's this thread I found that has someone's settings on it, but don't know if its good or how much this guy knows(no offense to him):
http://forum.xda-developers.com/showthread.php?t=1356211
Anyone got any insight or perhaps screenies of their optimally tested settings? VERY VERY appreciated to anyone that can help.
jgruberman said:
So I have a few apps... Voltage Control, SetCPU, No-Frills CPU... but I've honestly been a bit weary to use them. I want the best battery life since I'm a heavy user, but I also don't want to overclock/set voltage to a point where I'll screw up my phone. I'll admit that I'm a novice user when it comes to voltage/overclocking, but not when it comes to ROMs, kernels, bootloaders, etc. I work with those all the time, but really trying to get the most out of the battery and CPU.
There's this thread I found that has someone's settings on it, but don't know if its good or how much this guy knows(no offense to him):
http://forum.xda-developers.com/showthread.php?t=1356211
Anyone got any insight or perhaps screenies of their optimally tested settings? VERY VERY appreciated to anyone that can help.
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there is no rule. every cpu is different. very different. my captivate took a lot of effort to get a meer 1300 mhz but my infuses get 1600 no problem at all. some infuses wont go to 1600 but more will go to 1500 than galaxy s's. they probably held out the best testing cpu's for the higher clocked phone.
for battery life try clocking @ 800 mhz and dont use screen off profiles just because it looks like a good idea to slow the cpu when you arent really using it(causes problems if the max freq is too low with some kernels) and test stability with your uv settings, go down a little at a time, for max frequency uv from the top down, for battery life go from the bottom up and disable the upper freqs if they become unstable. this is because rapid voltage changes can contribute to instability. too much differential will cause crashes if the uv is extreme or the oc is extreme.
at some point though the cpu settings will have a limited effect. the radios use battery as well. manage your screen brightness and try edge only with the screen off using any number of apps that manage the radio. try one of entropys kernels to avoid a feature of the wifi chip (or was it bt) from sucking power when in proximity of another device with the same chip. turn off sync if you dont need push emails from gmail or real time facebook updates and if you really need battery life get in the habit of togging wifi and bt and gps on and off depending on need. i do none on this because i always found the battery life adequate on samsung phones but on my aria, well it was a must and prolly why people hate android. htc and battery life dont go together unless you manually manage the phone functions.
That's a great bunch of information. I currently keep my Brightness at 0%, GPS off, Wifi only ON when I'm at work when the charger is plugged in.
I guess I'm more concerned with the undervolting than the overclocking. I'd rather preserve the battery life with undervolting... the overclocking isnt a HUGE concern, but it'd be nice to see. Regardless, if you have any "ideal" UV settings, or ones that have worked for YOUR Infuse(assuming you have one), then I'd love to see them.
at one point i had -200mv on every freq from 100-1600mhz and no crashes. i started manually editing the uv script (voltage control is only able to write -200 into the script unless you have the pay version) and forgot what i ended up with. but my first infuse was exceptional in that area. some infuses freeze above 1400 mhz no matter what voltage settings are used. about -50 seems to be safe 99% of the time with minor or no overclock across the board but you could probably go -50 down low and -100 from 400mhz up to 1200 and -50 or -75 on overclock freqs. with underclock or atleast no overclock it's probably safe to go -100 to -150. it may be safe to go much more than that as well but on a small number of phones that might be too far as it is. cpus are made on such a small scale that microns of inconsistency make large percentages of difference. many dont pass testing and qc. some are borderline for the application, some are exceptional. the smaller the architecture gets the more potential the design has for speed but the larger the variance in performance is given a manufacturing technique. obviously the manufacturing gets better and better combating this so that they can make smaller architectures they also have redundancy built in, but sometimes they just disable features of a chipset and market it as an economy version if they have a low pass rate. ever see a 3 core cpu for a pc? most are manufactured as 4 cores and on many motherboards the bios can unlock the 4th core with somewhat unpredictable results.
Again, some really great info for the technical guys such as myself. What is the best way to test the UV settings? The built in tools and stuff in SetCPU? Or is there another way that would be more effective and/or would get more realistic results?
It seems like every phone can handle a different clock speed, is there is a tried and true way to find the optimal clock speed for your phone?
No as u say every phone acts on hes own so i dont think there is any software for this ( optimal overclock) but there is software for ocing it easy like setcpu or nstools... you can oc your cpu by raising it, and using it with multitasking and if it doesnt reboot in hour or two of heavy usage then go step higher. When it reboots try with step or two higher voltages and so on until you get highest cpu with moded voltages (not more than 2 steps) stable with no reboots. Ofc i wouldnt recommend this as you are not getting anything special from it and you risk your phone... btw optimal cpu speed is its own stock speed that is just pure logic xd
Though there is no agreed upon definition, to me the optimal cpu speed is not the stock speed, the stock speed is the standard safe speed. When a CPU is manufactured it invariably has defects, the number of defects dictates the speed at which it can run. For example, when they manufacture the i5 and the i7 they probably just take defective i7 chips and turn off two cores and call it an i5. (I don't know if they actually do this with the i5 and i7 but it's been common practice with just about every processor in the past.)
I guess I should use a different term like, maximum safe speed.
Trial and error is the best way to my knowledge, haven't heard of any phone apps adjusting clocks on the fly based on temp, inaccuracies, etc, like on a computer. You can feel the temp of the phone and it'll reboot at the smallest sign of instability, just don't set test profiles to set on boot.
And what you say is correct. Processes with similar imperfections are grouped, tested and sold under a given name with the benchmark being stock frequency and voltages. Common practice and very often you get some chips you can over clock til it expands out of its bracket and others which fail at everything but stock.
I'm running CM10, and it's running fine overclocked to 1600 MHz, yet the phone is factory clocked, (with a factory ROM), to 1200 MHz. Why? My phone seems to run perfectly fine using SmartAss2 management, but Samsung apparently purposely underclocks phones for some unknown reason. Obviously stability isn't a concern, or it would crash at 1600 MHz. Yet it is stable, so why is the default clock speed so slow? Considering the phone is perfectly stable at 1600 MHz, would it be possible to O/C my phone to 2 GHz, or would I risk frying my phone if I somehow managed to OC it by that much?
k-semler said:
I'm running CM10, and it's running fine overclocked to 1600 MHz, yet the phone is factory clocked, (with a factory ROM), to 1200 MHz. Why? My phone seems to run perfectly fine using SmartAss2 management, but Samsung apparently purposely underclocks phones for some unknown reason. Obviously stability isn't a concern, or it would crash at 1600 MHz. Yet it is stable, so why is the default clock speed so slow? Considering the phone is perfectly stable at 1600 MHz, would it be possible to O/C my phone to 2 GHz, or would I risk frying my phone if I somehow managed to OC it by that much?
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uhh well.... yea and no. there are a few things you need to understand about microprocessors. no two are alike. they are built on a scale of a few nanometers and any difference causes a significant difference. to keep production numbers up there is a line they have to draw between performance potential and stability. more chips will be stable at lower clocks so they pick an speed they can get a high production number out of. sometimes a whole line of chips is produced with exactly the same core. chips that pass the highest get boxed as the highest performing and priced. chips that dont pass will either have specific features turned off, cores turned off or be underclocked and sold as lower models. in addition to that the top performing models are actually over priced, and often many more pass the tests than they need so perfectly good processors are intentionally disabled to fill the market for lower speed processors, so yes the cpu may be "underclocked" in a sense. but i don't know if that really applies to the infuse because i don't know if there are any chips in the same family that have a higher rated clock speed, if there are they aren't used in phones.
in example, on my pc i have a 3 core processor, it's actually a 4 core and i can even turn the 4th core on in bios, but a certain percentage of that particular model of chip will be unstable with the 4th core active.
another thing to understand is how the clock speed is set. there is a buss and a table of multipliers and dividers. so as one part of the chip oscillates at one frequency the multipliers and dividers say how may times per oscillation the other components go. the cpu speed changes by changing these multiplier values. the problem is that there are only so many multipliers the cpu is designed to use. this is a hardware limitation and can't be overcome so at some point the only way to get more clock speed is to change the buss speed which affects the entire system and will cause instability in most cases. occasionally you can get around this if you change the multiplier values for other componants as well but it's probably not a good idea to mess with it. the hummingbird chip only has multipliers to go to 1600mhz regardless of stability unless you mess with the buss, one developer got the galaxy s to 1700 with buss overclocking but some things didn't really work at that speed and it took a lot of changes to other system clocks. snapdragon chips can go to higher clocks and process numbers better but the hummingbird is better for graphics and multimedia which is more important on a modern phone imho.
so yeah 1600 is it, as far as practicality goes anyway. there are a few infuses that can only go to 1400-1500 as well and galaxy s phones which have the same clock limitations but are only rates for 1000mhz rarely go to 1600, but a few do, my captivate was absolutely peaked out at 1300, believe me i tried to get it higher, i tried a lot of things with voltages to try to get it stable, but even 1300 took some doing. it took a long time before developers even produced a kernel for the sgs that used clocks over 1200 because many of the early builds of the sgs series were much like mine and were not stable at high speeds.
Beautiful. :thumbup:
Sent from my SGH-I997 using xda app-developers app
It seems to me many people overclock their HOX up to around 2ghz through various kernels/ROMs. I'm relatively new to Android phones but I do have a fair amount of OC experience on PC. The thing is, on PC the OC is generally well studied/tested by many people with well established thresholds, and people often upgrade their cooling system to accommodate OC. If stock cooler is used, there are usually established conservative limits. Furthermore, there are programs that stress test the setup to detect any instability. It's known that OC decreases hardware's lifespan, but if you do it right, that decrease can be negligible because of the realistic lifespan of PC.
Our phone is tiny and its cooling is not upgradable. If we overclock it by 30%, what effect will it have on its lifespan? Is there something about these S4 CPU's that I don't know about? Were they made to be able to easily handle the OC without any significant heat increase?
Please share your thoughts.
I'm not sure the true clock speed of the krait but I've read that most CPUs are under clocked by default
So I would think the impact would depend on its true clock speed
It also depends on how long you intend on keeping the phone. I change phones quite often.
If you intend on keeping it two years then I'd suggest just be safe and not sorry. This phone is fairly new and not much is know of long term issues quite yet
Sent from my One X using Tapatalk 2
i know the S4 can be clocked at different speeds by default (1.5-1.7 GHz Dual-core Krait). there is also superpi for android to test stability. it seems 1.5 - 2.0 GHz doesn't give much of a performance boost as far as benchmarks go imo. If we could somehow manage to tweak memory timings like on a pc that would be awesome.
OC = shorter life........to what extent I cannot say. But it's a fact
Sent from my HTC One X+ p_type 0.91.0
My P3 that was a stock speed of 733 an runs at 1.8ghz for last 6 years with factory cooling says don't worry about it.
Also, i couldn't hit 229ms in pi until 2ghz.
If your worried about shortening the life span, by over clocking, its not for you honestly.
WR
Sent from my One X
you overclocked a Pentium 3 733 to 1.8 ghz? i don't believe that at all..
DvineLord said:
you overclocked a Pentium 3 733 to 1.8 ghz? i don't believe that at all..
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You are correct, its a typo, it should read 1.4 and not 1.8.
WR
Sent from my One X