I have a few questions about OC/UV kernels or rather the theory behind them, particularly the UV part.
My natural instinct is to believe that when the voltage is dropped that the amps would increase so the CPU would still have the same amount of power to run the CPU at a particular frequency. This of course would negate any advantage in UV. I assume that my assumption is wrong or someone that really knows something would have pointed it out.
On the practical side of things, if the above is not true does the phone/cpu use the same amount of power if it is running at 216 Mhz with 770 mV as it does running at 400 Mhz with 770 mV. Same question would also apply to high frequencies that are UV and their relationship to heat generation.
Not sure about smartphones, but with my computer, I can drop 10 watts just from under volting when idle. Under clocking makes an even bigger difference. I'll get some exact numbers in a few mins, this got me wondering lol.
Edit:
At the wall my PC will pull 111 watts @ 1.6GHz idle. @ 4.5GHz it pulls 137 watts on idle.
I wish I had a link I could provide, but the basic science is this (learned this from Calkulin, Ziggy, and trial and error with my evo):
uV:
When you uV your cpu, each frequency step draws less power. For example, a non-uV'd cpu might draw 1300 mV at 1000 MHz whereas a uV'd cpu might draw 1225 or 1250 mV at 1000 MHz. There is no sacrifice in performance. You also get a cpu that runs cooler because it is drawing less power. The combination of these things means better batter life because you are drawing less power (obvious) and generating less heat (heat is one of the enemies of Li-ion batteries holding a charge).
But not all chips are the same, and some tolerate lower voltages better than others. If a particular voltage is too low, you get crashes, reboots, and other things like that because voltages that are too low make things unstable.
OC:
The theory behind OC is that the higher frequencies allow you to complete tasks faster. If the cpu can complete a certain task in a shorter period of time, it will be in use for less time overall, thereby allowing it to return to its idle frequency faster and stay in its idle frequency state longer. Again, this combination increases battery life because the power drawn from the battery is less. You can think of this as a "race to the finish" situation.
For example, if you OC to 1100 MHz, you might complete a task in 1.5s, whereas at 1000 MHz that same task might take 2s. The cpu actually works for a shorter time and returns to idle 0.5s faster. Add this up over an entire day, and your cpu actually spends more time at idle when OC'd than when not OC'd.
Again, just as with the uV, not all chips can tolerate maximum OC and just become unstable. That's why you've seen some G2x chips be able to run at 1500 MHz and be stable, while others can only tolerate 1300 MHz. Instability by trying to OC the cpu too much will lead to the same types of problems as lowering the voltages too far.
OC & uV together:
When you OC and uV, you allow the cpu to run at a higher frequency and draw less power at the higher frequency. This means you get tasks done faster and use less power to complete them, which allows the cpu to return to its idle frequency faster.
This is a real-world hypothetical: Imagine you have a cpu running at 1100 MHZ at 1300 mV and 1000 MHz at 1300 mV. When this is the case, your OC'd/uV'd cpu completes a task faster (in 1.5s rather than 2s) and actually ends up drawing less power than the non-OC'd/non-uV'd cpu because it completes the task faster and returns to idle sooner. When you add this up over an entire charge cycle, you should get better battery life.
Related
I tried to search but was unsuccessful to find the information that I wanted.
Can someone tell me what are the recommended safe undervolt settings for the transformer?
I'm running prime 1.9 with clemsyn-blades 1.6a.
Thx
Sent from my Transformer TF101 using Tapatalk
steve.garon said:
I tried to search but was unsuccessful to find the information that I wanted.
Can someone tell me what are the recommended safe undervolt settings for the transformer?
I'm running prime 1.9 with clemsyn-blades 1.6a.
Thx
Sent from my Transformer TF101 using Tapatalk
Click to expand...
Click to collapse
I don't know what the stock settings are but I can tell you the process I followed when I OCed my tablet. Install the custom kernel and rom you want. Then install an app to modify frequency and voltages. I use setCPU but pimpmycpu works also.
1. Find the highest clock you can attain with the provided overvolt from the kernel. To do this just start at the highest frequency and see if the tablet reboots or locks during a stress test. Some people play games to stress. I use the built in stress tester in SetCPU. Make sure to apply the higher frequency for testing but not to apply settings on reboot or you could get stuck in a reboot loop (or so I am assuming the kernel might reset to 1 GHz when a hard lock occurs).
2. Once you have the maximum Frequency (for me it was 1.644 MHz) then start lowering the voltage for that frequency only until you loose stability. I can undervolt 1.644 by -75 mV. If I go upto -100 then I get random reboots. I go in -25 mV increments but you could narrow it down even more by going with -10 or even -5 intervals.
3. Take the offset you got (in my case -75 mV)on the highest frequency and apply it to every frequency above 1 GHz and see if this is stable. If not then slowely increase voltage until you gain stability again.
4. (Optional) Then start undervolting stock frequencies from 216 MHz to 1 GHz. Every tablet is different but (I have heard) this could cause sleep issues. I undervolted all frequencies from above 216 to 1000 GHz by -25 Mv without any issues. I may bring it down slowely by increments of-5 or -10 until I run into some issues.
5. (Optional) Undervolt 216 MHz as low as possible to save standby battery power. I undervolted my 216 MHz to 725 mV (even though SetCPu goes lower the kernel is locked at this). Which helps keep my battery levels up when the tablet screen is off and not in use.
Hints: To test that a voltage is okay at a certain frequency then make sure to set your max to the frequency level you want to test. If you set the max at 1544 and undervolt 1 GHz you will never know if it is okay because when you stress it it will blow right past 1 GHz upto 1544 and the voltage for that will take over.
If you have any questions please let me know.
Bjd223 said:
I don't know what the stock settings are but I can tell you the process I followed when I OCed my tablet. Install the custom kernel and rom you want. Then install an app to modify frequency and voltages. I use setCPU but pimpmycpu works also.
1. Find the highest clock you can attain with the provided overvolt from the kernel. To do this just start at the highest frequency and see if the tablet reboots or locks during a stress test. Some people play games to stress. I use the built in stress tester in SetCPU. Make sure to apply the higher frequency for testing but not to apply settings on reboot or you could get stuck in a reboot loop (or so I am assuming the kernel might reset to 1 GHz when a hard lock occurs).
2. Once you have the maximum Frequency (for me it was 1.644 MHz) then start lowering the voltage for that frequency only until you loose stability. I can undervolt 1.644 by -75 mV. If I go upto -100 then I get random reboots. I go in -25 mV increments but you could narrow it down even more by going with -10 or even -5 intervals.
3. Take the offset you got (in my case -75 mV)on the highest frequency and apply it to every frequency above 1 GHz and see if this is stable. If not then slowely increase voltage until you gain stability again.
4. (Optional) Then start undervolting stock frequencies from 216 MHz to 1 GHz. Every tablet is different but (I have heard) this could cause sleep issues. I undervolted all frequencies from above 216 to 1000 GHz by -25 Mv without any issues. I may bring it down slowely by increments of-5 or -10 until I run into some issues.
5. (Optional) Undervolt 216 MHz as low as possible to save standby battery power. I undervolted my 216 MHz to 725 mV (even though SetCPu goes lower the kernel is locked at this). Which helps keep my battery levels up when the tablet screen is off and not in use.
Hints: To test that a voltage is okay at a certain frequency then make sure to set your max to the frequency level you want to test. If you set the max at 1544 and undervolt 1 GHz you will never know if it is okay because when you stress it it will blow right past 1 GHz upto 1544 and the voltage for that will take over.
If you have any questions please let me know.
Click to expand...
Click to collapse
Cool. I'll give this a try.
Sent from my Nexus S using Tapatalk
I get a stable undervolt at -50 on all cpu steps which is pretty good. This should save loads of battery.
Sent from my Nexus S using Tapatalk
steve.garon said:
I get a stable undervolt at -50 on all cpu steps which is pretty good. This should save loads of battery.
Sent from my Nexus S using Tapatalk
Click to expand...
Click to collapse
I started at the top and went down every stepping from 1624 to 1000 and found out the lowest stable frequency and then added 10 to be safe to each one. I am currently at
1624 (-70)
1592 (-80)
1544 (-180)
1472 (-80)
1424 (-160)
1336 (-185)
1232 (-185)
1000 (- 110) which is 990 mV
I then set every stepping under 1 GHz frequency that was above 990 mV to 990 mV as if it can run at 1 GHz at that voltage then any speed under that will run fine at that voltage also. I have some more stability testing to do but I think I got it pretty much nailed down for my device. I may go through all the sub 1 GHz frequencies but it does take some time to run a stress test under each stepping.
Also I have never had any sleep issues but that is something to look out for. I also wonder how temperature affects stability as I have never gotten it above 40c. The pad might benefit from a 1 or 2mm thermal pad squeezed between the CPU and the back bezel (if it will fit).
Does anyone know that tjunction max for a Tegra2? I have a profile set up in SetCPU that sets the CPU frequency at 1 GHz if the CPU gets above 42 because I saw something similar in the Clemsyn rom but don't really know when the CPU will start to throttle itself at or shut off.
I am trying to find stock voltages for different devices because it seems like some mfgs are undervolting to save battery on some tablets.
Bjd223 said:
I started at the top and went down every stepping from 1624 to 1000 and found out the lowest stable frequency and then added 10 to be safe to each one. I am currently at
1624 (-70)
1592 (-80)
1544 (-180)
1472 (-80)
1424 (-160)
1336 (-185)
1232 (-185)
1000 (- 110) which is 990 mV
I then set every stepping under 1 GHz frequency that was above 990 mV to 990 mV as if it can run at 1 GHz at that voltage then any speed under that will run fine at that voltage also. I have some more stability testing to do but I think I got it pretty much nailed down for my device. I may go through all the sub 1 GHz frequencies but it does take some time to run a stress test under each stepping.
Also I have never had any sleep issues but that is something to look out for. I also wonder how temperature affects stability as I have never gotten it above 40c. The pad might benefit from a 1 or 2mm thermal pad squeezed between the CPU and the back bezel (if it will fit).
Does anyone know that tjunction max for a Tegra2? I have a profile set up in SetCPU that sets the CPU frequency at 1 GHz if the CPU gets above 42 because I saw something similar in the Clemsyn rom but don't really know when the CPU will start to throttle itself at or shut off.
I am trying to find stock voltages for different devices because it seems like some mfgs are undervolting to save battery on some tablets.
Click to expand...
Click to collapse
-180 in some frequencies!! Thats just insane. I've got to try this.
FYI, you don't have to lower voltage for all upper 1ghz frequencies. If your running at 1544 for exemple. The cpu will never touch the frequencies between 1000 and 1544. After the 1000 its a direct step to whatever frequency your overclocking too. You can monitor this in setcpu.
I cannot undervolt as precise as you can. For some reason setcpu only let me do 25mv increment...
Sent from my Nexus S using Tapatalk
I have undervolted by -175 on all frequencies, obviously 216Mhz is locked but all seems pretty stable after some testing. No sleep death either so I'm going to carry on testing.
steve.garon said:
-180 in some frequencies!! Thats just insane. I've got to try this.
FYI, you don't have to lower voltage for all upper 1ghz frequencies. If your running at 1544 for exemple. The cpu will never touch the frequencies between 1000 and 1544. After the 1000 its a direct step to whatever frequency your overclocking too. You can monitor this in setcpu.
I cannot undervolt as precise as you can. For some reason setcpu only let me do 25mv increment...
Sent from my Nexus S using Tapatalk
Click to expand...
Click to collapse
In SetCPU do not use the slider use the keyboard and type in the exact number you want.
I wanted to figure out every stepping in case I wanted to switch to a lower frequency but yeah most poeple don't have to do this.
The lowest stable I have gotten is -190 but feel like adding 10 padding will ensure stability.
I will probably do the sub 1 GHz frequencies today or tomorrow.
Bjd223 said:
In SetCPU do not use the slider use the keyboard and type in the exact number you want.
I wanted to figure out every stepping in case I wanted to switch to a lower frequency but yeah most poeple don't have to do this.
The lowest stable I have gotten is -190 but feel like adding 10 padding will ensure stability.
I will probably do the sub 1 GHz frequencies today or tomorrow.
Click to expand...
Click to collapse
I didnt even noticed I could use the keyboard...
I finally settled to -25 @216, -50 under 612 and -100 over 612. And everything is stable
Sent from my Nexus S using Tapatalk
I have tested each voltage. I am under the impression that 725 mV is the kernel minimum in the Clemsyn kernel so once I hit that I just set every frequency under that too 725. I will eventually go through and stress test every frequency @ 725 to make sure everything is a-okay but I am sure it is.
Here is my list incase anyone wants a place to start.
1680 MHz (-000) I can not overclock to this freuqency.
1624 MHz (-070) 1380 mV
1592 MHz (-080) 1345 mV
1544 MHz (-180) 1220 mV
1472 MHz (-080) 1220 mV
1424 MHz (-160) 1115 mV
1336 MHz (-185) 1065 mV
1232 MHz (-185) 990 mV
1000 MHz (-215) 885 mV
0912 MHz (-215) 835 mV
0816 MHz (-235) 790 mV
0760 MHz (-215) 760 mV
0608 MHz (-225) 725 mV
0456 MHz (-100) 725 mV
0312 MHz (-075) 725 mV
0216 MHz (-025) 725 mV
Clemsyn said the minimum mV in his kernel but I can't seem to find the thread, but I think it was 725. If I find out it is something lower I will go through the lower ones until I hit the minimum.
Also please note that everything above 1 GHz has +10 mV padding added to it above the lowest stable I could find. Everything below 1 GHz only has a +5 mV padding on it. So for example I actually hit a -240 w/o any issues @ 816 MHz.
I tested in +/-5 mV increments but if you wanted you could narrow it down even further.
EDIT: Also after some testing it looks like it does use frequencies between 1 GHz and your max. I have it set to 1644 and it does hit 1232 MHz occasionally.
Bjd223 said:
I don't know what the stock settings are but I can tell you the process I followed when I OCed my tablet. Install the custom kernel and rom you want. Then install an app to modify frequency and voltages. I use setCPU but pimpmycpu works also.
1. Find the highest clock you can attain with the provided overvolt from the kernel. To do this just start at the highest frequency and see if the tablet reboots or locks during a stress test. Some people play games to stress. I use the built in stress tester in SetCPU. Make sure to apply the higher frequency for testing but not to apply settings on reboot or you could get stuck in a reboot loop (or so I am assuming the kernel might reset to 1 GHz when a hard lock occurs).
2. Once you have the maximum Frequency (for me it was 1.644 MHz) then start lowering the voltage for that frequency only until you loose stability. I can undervolt 1.644 by -75 mV. If I go upto -100 then I get random reboots. I go in -25 mV increments but you could narrow it down even more by going with -10 or even -5 intervals.
3. Take the offset you got (in my case -75 mV)on the highest frequency and apply it to every frequency above 1 GHz and see if this is stable. If not then slowely increase voltage until you gain stability again.
4. (Optional) Then start undervolting stock frequencies from 216 MHz to 1 GHz. Every tablet is different but (I have heard) this could cause sleep issues. I undervolted all frequencies from above 216 to 1000 GHz by -25 Mv without any issues. I may bring it down slowely by increments of-5 or -10 until I run into some issues.
5. (Optional) Undervolt 216 MHz as low as possible to save standby battery power. I undervolted my 216 MHz to 725 mV (even though SetCPu goes lower the kernel is locked at this). Which helps keep my battery levels up when the tablet screen is off and not in use.
Hints: To test that a voltage is okay at a certain frequency then make sure to set your max to the frequency level you want to test. If you set the max at 1544 and undervolt 1 GHz you will never know if it is okay because when you stress it it will blow right past 1 GHz upto 1544 and the voltage for that will take over.
If you have any questions please let me know.
Click to expand...
Click to collapse
Thanks for this mate. I followed your guide exactly and I'm using clems 16? Kernel completely stable at all frequencies including the undervolting!
Based on my testing you need ~ a +15 to +25 mV over stable CPU voltage to get stable 3D GPU.
I found that I could run hours of "Stress CPU" without any issues at a voltage but during stressful 3D games that are using CPU + GPU cores, at that same frequency, the machine would FC the app, reboot or lock. I have also noticed that the closer you are to the stable voltage different things will happen.
Far off - machine will usually reboot
Closer - machine will usually hard lock
Even closer - Apps will FC, widgets will act strange (like invert colors, black blocks for backgrounds, etc.)
So what I do now is I test with Dungeon Defenders at the main menu. Its seems that if you can last 1 hr at the Dungeon Defenders menu you are GTG. If you actually play the game then 1 stage is what I use to test.
Bjd223 said:
I don't know what the stock settings are but I can tell you the process I followed when I OCed my tablet. Install the custom kernel and rom you want. Then install an app to modify frequency and voltages. I use setCPU but pimpmycpu works also.
1. Find the highest clock you can attain with the provided overvolt from the kernel. To do this just start at the highest frequency and see if the tablet reboots or locks during a stress test. Some people play games to stress. I use the built in stress tester in SetCPU. Make sure to apply the higher frequency for testing but not to apply settings on reboot or you could get stuck in a reboot loop (or so I am assuming the kernel might reset to 1 GHz when a hard lock occurs).
2. Once you have the maximum Frequency (for me it was 1.644 MHz) then start lowering the voltage for that frequency only until you loose stability. I can undervolt 1.644 by -75 mV. If I go upto -100 then I get random reboots. I go in -25 mV increments but you could narrow it down even more by going with -10 or even -5 intervals.
3. Take the offset you got (in my case -75 mV)on the highest frequency and apply it to every frequency above 1 GHz and see if this is stable. If not then slowely increase voltage until you gain stability again.
4. (Optional) Then start undervolting stock frequencies from 216 MHz to 1 GHz. Every tablet is different but (I have heard) this could cause sleep issues. I undervolted all frequencies from above 216 to 1000 GHz by -25 Mv without any issues. I may bring it down slowely by increments of-5 or -10 until I run into some issues.
5. (Optional) Undervolt 216 MHz as low as possible to save standby battery power. I undervolted my 216 MHz to 725 mV (even though SetCPu goes lower the kernel is locked at this). Which helps keep my battery levels up when the tablet screen is off and not in use.
Hints: To test that a voltage is okay at a certain frequency then make sure to set your max to the frequency level you want to test. If you set the max at 1544 and undervolt 1 GHz you will never know if it is okay because when you stress it it will blow right past 1 GHz upto 1544 and the voltage for that will take over.
If you have any questions please let me know.
Click to expand...
Click to collapse
I always wanted to learn more about the mV and CPU speed stuff. I always install rom, install kernel of the one I heard the better is and that's it. Never had touched the voltage measure in any of my android device. Yeah i know, so noob.
Thanks for this how to info, I think I will play around a bit later. Right now I'm struggling with my self on wish of the 3 roms available install and stay.
Had to remove undervolt this weekend since my camera wouldnt start anymore. I'll have to redo all the tests I was doing but test for camera too. The tablet would just freeze as soon as I opened the camera app
Sent from my Nexus S using Tapatalk
steve.garon said:
Had to remove undervolt this weekend since my camera wouldnt start anymore. I'll have to redo all the tests I was doing but test for camera too. The tablet would just freeze as soon as I opened the camera app
Sent from my Nexus S using Tapatalk
Click to expand...
Click to collapse
My camera does not work either. I just figured it was Clemsyns kernel not the OC. I don't know anything about cameras but maybe they use a lot of voltage so the voltage to the CPU dips.
I never used the camera personally, but I will test it some and see what additional mV you need over stable to get the camera working.
Also I noticed the more you undervolt (it seems to me) the harder it is to undock with an app open. usually instead of reloading they FC or lock the device so i just make sure to hit the home key before I undock then alt tab right back into the app.
Bjd223 said:
My camera does not work either. I just figured it was Clemsyns kernel not the OC. I don't know anything about cameras but maybe they use a lot of voltage so the voltage to the CPU dips.
I never used the camera personally, but I will test it some and see what additional mV you need over stable to get the camera working.
Also I noticed the more you undervolt (it seems to me) the harder it is to undock with an app open. usually instead of reloading they FC or lock the device so i just make sure to hit the home key before I undock then alt tab right back into the app.
Click to expand...
Click to collapse
My camera did not work at 912 MHz at stock voltage on 17b but now on 18 I can do my normal undervolt settings and the camera works fine.
Since installing builds 29, 30, 31 I have noticed my battery life shrinking and the xoom running warmer. Am I imagining things or are these builds overclocked upon flashing?
Nope, not by default. I'm running EOS 32 and it came set up like this:
Governor: Interactive
Minimum Frequency: 216 MHz
Maximum Frequency: 1000 MHz
Maybe you can use an app like System Tuner to undervolt your Xoom? Not sure what else could be draining your battery so fast while warming your device.
It could be my imagination and maybe I am just using the device more and giving it a workout when playing with all these EOS builds.
Thanks for the clarification.
Can someone just let me know what overclocked exactly means ?
is it helps to make mobile/tablet faster ?
CPUs have the ability to run faster than they are clocked by the manufacturer. The tablet ships with a CPU clock speed of 1 GHz. This speed is specified because the CPU manufacturer has deemed it the optimum speed (in terms of stability and possibly power consumption) for that particular CPU. By modifying the kernel, you can add the ability to change this maximum (and minimum) threshold. Theoretically, yes, if you increase the clock speed, your tablet will run faster.
The clock speed is how many cycles a CPU can do per second. So, at 1 GHz, a CPU executes ~1,000,000,000 cycles per second. By setting the maximum speed to 1.5 GHz, your CPU can now execute ~1,500,000,000 cycles per second. A CPU also has an instructions per cycle rating. So the more cycles you can execute in a second, the more instructions your CPU can process in that second.
You must keep in mind that when you increase the clock speed, you may sacrifice battery life and/or stability (higher frequency needs higher voltage). Additionally, even though we all have the same CPU in our tablets, there are small variances. I may have no stability issues running at 1.7 GHz while you may suffer boot loops running at 1.7 GHz. Furthermore, running at a higher clock speed may cause more heat and electronics don't operate very well when overheating.
Finally, the governors are used to regulate the clock speed. Just because your CPU is clocked to 1 GHz, doesn't mean it's running at that speed 100% of the time. If it's sitting idle, it may be running at ~0.250 GHz (250 MHz). Then, when you wake up the tablet and open an application, the governor realizes you need more CPU power so it increases the "maximum" until either 1) You no longer need additional power 2) You've reached the maximum threshold set by the kernel.
"The clock speed is how many executions a CPU can do per second. So, at 1 GHz, a CPU can process ~1,000,000,000 instructions per second. By setting the maximum speed to 1.5 GHz, your CPU can now execute ~1,500,000,000 instructions per second"
Not sure if I am misunderstanding your lesson. Please understand this no attempt to troll or argue, but Clock speed is a reference of the frequency of the processor. They are basically saying your processor has an operating frequency of 1 Ghz. Instructions per second is measured by IPS (instructions per second). For instance, My AMD Quad Core processor operates at 3.0 Ghz but can handle 42,820 MIPS. They are not directly proportionate.
terrymc2708 said:
"The clock speed is how many executions a CPU can do per second. So, at 1 GHz, a CPU can process ~1,000,000,000 instructions per second. By setting the maximum speed to 1.5 GHz, your CPU can now execute ~1,500,000,000 instructions per second"
Not sure if I am misunderstanding your lesson. Please understand this no attempt to troll or argue, but Clock speed is a reference of the frequency of the processor. They are basically saying your processor has an operating frequency of 1 Ghz. Instructions per second is measured by IPS (instructions per second). For instance, My AMD Quad Core processor operates at 3.0 Ghz but can handle 42,820 MIPS. They are not directly proportionate.
Click to expand...
Click to collapse
You're right and wrong
IPS is a function of clock speed so they ARE directly proportionate.
(Clock speed) X (instructions per clock) = IPS
I used "instructions" to simplify the example but you're right, I should be using another word.
Thanks for pointing that out!
Thanks skinien
I'm having motorola xoom ... planning to root it to have ICS ... any idea what will be optimal overclock speed for it .... mostly for playing games on it
nash.android said:
Thanks skinien
I'm having motorola xoom ... planning to root it to have ICS ... any idea what will be optimal overclock speed for it .... mostly for playing games on it
Click to expand...
Click to collapse
From what I've seen, a lot of people stay around 1.5. Just make sure you don't click "set on boot" immediately. Use it for a while too make sure its stable at your chosen frequency.
Sent from my ADR6400L using XDA App
On ICS, mine is super stable at 1.4Ghz. My crashes, no reboots. And I'm using the Lagfree governor, so clearly I'm not locked in at 1.4 all the time. That's just the max speed based on CPU intensive activity...
Widgets not shown in Applications
I uploaded November 6th build on my Xoom Wifi. I have the following error - clock stopped & then I did not see Widgets under apps. Please let me know how to invoke widgets.
Thanks,
Pingala
Coming from the HTC Desire, where SetCPU was the only to manage the CPU, I have developed a habit of using SetCPU with several frequency profiles and different governors for various situations. For instance, I use battery<80, <60, <40, <30, screen off, temp >40, >50, and a charging profile. For governors I use lulzactive2 for higher frequency ranges, interactive for mid range frequencies and on demand for the lower frequencies. Oh, this is all with the latest matr1x kernel.
Seeing how a lot of ROMs allow extensive controll of the CPU I was wondering if it wouldn't be more efficient to just set a min/max frequency, chose a governor, turn deep idle on (which is off while I'm using SetCPU) and leave it be.
What are your thoughts and experiences on the matter?
/// endmessage / COMPUTOR5000
profile ? that's completely unnecessary...
just set governor and min-max is enough.
we have NSTOOL, so looks like extended ROM controll also not necessary because not good enough compare to NSTOOL , but lots lots ROM has it build-in
I've never bothered with profiles. I can feel if the phone needs a break from the heat and performance is good for me with 100/1200 set and slight undervolting.
Battery life while idling won't change, only while using intensive apps, and with deep idle working and max freq screen off, music playback and the likes drains very little battery.
Try it and see, you need to be comfortable with it.
I agree with qtwrk. Profiles are, in most cases, detrimental. The following is especially true since Deep Idle was implemented: always let the CPU run as fast as possible to save energy. Sounds counterintuitive, but here's why: while lower CPU frequencies in general consume less energy PER TIME than higher CPU frequencies, the faster the CPU can finish it's job, the faster it can return to energy saving states. So in the end, reducing CPU frequency actually uses more energy... Just overclock to save values, use undervoltage to set lowest possible voltage values and go to sleep.
What's the minimum you can set the screen off max frequency so that music playback isn't choppy?
Also, is the phone always idle on screen off, or does music playback, or any other activity make the phone come out of idle, even if the screen is still off?
/// endmessage / COMPUTOR5000
zyrill said:
I agree with qtwrk. Profiles are, in most cases, detrimental. The following is especially true since Deep Idle was implemented: always let the CPU run as fast as possible to save energy. Sounds counterintuitive, but here's why: while lower CPU frequencies in general consume less energy PER TIME than higher CPU frequencies, the faster the CPU can finish it's job, the faster it can return to energy saving states. So in the end, reducing CPU frequency actually uses more energy... Just overclock to save values, use undervoltage to set lowest possible voltage values and go to sleep.
Click to expand...
Click to collapse
Very good point, for exemple cpu at 1000 MHz takes 1100 juices per second and 10 seconds to finish a task, total cost 10 x 1100 (11000 ) juice
If it runs at 1200 MHz takes 1200 juices per second, same task only needs 8.34 seconds, 8.34 x 1200 (10008) juices... this isn't real just number assumption and theoretically appears that way
Sent from my Nexus S using xda premium
I agree with everything that was said here and actually posted about this very topic earlier on in the matr1x thread in regards to the lulzactive settings. People putting settings too much towards battery saving are actually not getting battery savings. They are making the CPU run longer and therefore more cycles and more power. Profiles are a bad idea too. They cause problems.
I decided to ask hear instead of creating new thread, etc.
In the amazing post of droidphile http://forum.xda-developers.com/showthread.php?t=1369817 there's an information about SGS II, that
'energetically efficient' frequency for CPU is 200 mhz
Click to expand...
Click to collapse
(it's Cortex-A9).
And what about Cortex-A8 on Nexus S?
droidphile also says that on Milestone (Cortex-A8) 550Mhz is the frequency used in the calculations based on the optimal energy to run. Don't know what's the source of this info...
My phone runs at 750 mV at 200 Mhz but it can also run 750mV at 368Mhz.
So would it affect my battery to leave the min at 368Mhz? Does the phone still consume the same amount of battery even though the frequency would be higher?
I'd imagine it would draw my current so it'd drain your battery faster.
Yes it will definitely drain your battery faster
Which drain more battery, the undervolt value of -100mV or -140mV?
Hi everyone!
Could you help me understand this:
(Voltages / mV: 650, 675, 850, 975, 1075, 1225)
Look at the behavior at low frequencies. I can undervolt by up to -450mV, and it is running stable, which should not be possible. This would be far more efficient than the CPU of the Nexus 10. According to the idealized relation P ~ f * V^2, it would consume only 40% of the power that it needs with default settings.
At the high frequencies, however, I could confirm that SetCPU works, as the cellphone crashes like they usually do when you UV too much.
Is the hardware voltage control of this thing not scaling down properly?
Will my phone bite into my finger to get those calories otherwise?
Or do we own the best piece of hardware out there?
Are your phones weird, too?
Cheers,
ping
Image updated. I had to fix some occasional sleeps of death. Increasing the 100MHz and 200MHz voltages did the trick.
Still, the power drain caused by the CPU in the low frequency range is reduced by more than 60% for me.
I strongly recommend undervolting this crazy thing.