SetCPU, Underclocking


  1. IzelTokatl

    IzelTokatl Well-Known Member

    For those that haven't noticed. SetCPU does work on the Rezound with root. The kernel apparently supports under clocking (not overclocking at the moment, this requires a custom kernel).

    I've tested the cpu and confirmed the clock speeds with System Panel. I've been pretty stable at 918mhz which should show some decent battery improvement with little to no difference in general performance. I haven't tested with games if it shows signs of lag.

    Others may want to play around while we wait for full root and custom kernels.

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  2. trophynuts

    trophynuts Well-Known Member

    just curious

    what happens after you reboot?
  3. IzelTokatl

    IzelTokatl Well-Known Member

    we currently all lose root. So nothing, it goes back to stock until you enable root again, then enable SetCPU.
  4. trophynuts

    trophynuts Well-Known Member

  5. BlueBiker

    BlueBiker Well-Known Member

    I'm not sure what the value of forced underclocking is, since the Rezound already automatically underclocks both of its Snapdragon cores when there's no task running. Phone CPUs these days have extremely sophisticated power saving modes, so I suspect all you're doing is making the phone laggier anytime it wakes up and has something to perform.

    There's also speculation that an underclocked CPU actually consumes more battery because it must continue running longer to accomplish a task before it can put itself back to sleep.
  6. IzelTokatl

    IzelTokatl Well-Known Member

    Um, are we forgetting the fact that the new nexus has and under clocked cpu? Also, on my droid 3 if I over clock it the battery it does drain faster. Im not entirely sure this theory is sound. But I seriously can be =-), technology does change. Im still testing battery drain with the under clock though.
  7. BlueBiker

    BlueBiker Well-Known Member

    Good questions. I don't think it's ever been established whether Nexus was released at 1.2GHz to conserve battery, reduce heat, or whether there were manufacturing yield problems. The Archos G9 was also originally supposed to ship with the same OMAP4460 as the Nexus clocked at 1.5GHz, but they ran into problems. FWIW, the iPhone 4S' A5 chip is supposedly rated for 1GHz but runs at 800MHz.

    One kewl feature about OMAP4 chips is that in addition to the dual-A9 bada$$ cores, there are also a pair of extra low power M3 cores that automatically get swapped into action at low clock rates to keep tasks ticking along when not much is happening on the phone. So if some lazy background process is doing something, it may be running on the M3's with the A9's totally asleep.
    trophynuts likes this.
  8. pwned

    pwned Well-Known Member

    Why are you losing it after a reboot? I've had it enabled on mine and it still works after a reboot. I did unlock and perm root it with one clickthough. Im actually getting ready to flash a new bamf rom on it
    junenicolas likes this.
  9. trophynuts

    trophynuts Well-Known Member

    when the op originally posted this it was before the Gift that HTC Dev Unlock gave the community yesterday lol. At the time there was still only temp root.
    IzelTokatl likes this.
  10. EarlyMon

    EarlyMon The PearlyMon Moderator

    The cpu clocks in the Rezound are asynchronous (separate for each core) and have a minimum preset to (I believe) 384 MHz.

    In addition, one of your cpu cores will actually shut down when not in use.

    I found no benefit to underclocking my S3 processor to below 200 MHz (with the appropriate custom kernel).

    Also, note that SetCPU in Gingerbread tends to eat more battery than it saves when underclocking - you'll find a lot of SetCPU use in your power use profiles.

    I expect that very soon (if not already as I type this) you'll find kernel/rom packages that allow you to define min/max clock set points for overclocking - when that day comes, drop SetCPU in favor of that. ;)

    Please note - SetCPU will direct you how to create a file on your sd card that you can flash that will disable SetCPU. Do that. In the event you play around too much, you can send your phone into a bootloop - that flashable "turn-off" file will fix that. You can be one sad panda without it.

    By the way - if you like eye candy (and who doesn't? I sure do) try Quick System Info Pro, free in the Market, and go thru settings to show CPU clock speed in your notification pull-down. Then check it from time to time. You'll see that your two core are indeed running at independent speeds and that sometimes, you're only running one of the cpu cores.

    Note - not all monitor apps are capable of showing the separate clock speeds of the Qualcomm S3. The rest of the dual cores out there are clocked synchronously - one speed - so some utilities are lagging behind your phone's technology.

    Also, note that depending on tasks running, both cores can and will be used to max capacity. There's a lot of nonsense floating around that that's not true until you get ICS. ICS will simply be an upgrade to how tasks are managed for higher efficiency running on a dual core.

    Let's see - pics or it didn't happen:

    2011-08-24_23-22-29.jpg

    3vo-at-work.jpg

    Note - the System Panel Lite not showing a bar level for cpu speed is an idiosyncrasy of it not getting the dual core clocks, as warned previously.

    System Tuner, also free in the Market, does show both cpu cores accurately. Note you will find at times that one of the cpu cores will sometimes drop and then show "offline" in place of a clock speed.

    Hope this helps! :)

    PS - If/when you do go with a kernel/rom with an overclocking daemon instead of SetCPU, you can easily control it using System Tuner. System Tuner and Quick System Info Pro totally rock.
    BlueBiker and leroybrute like this.
  11. IzelTokatl

    IzelTokatl Well-Known Member

    Yes, I know setCPU is a drain, and the optimal choice is to write to the system files so there is no app CPU load. But, it was just a discovery PRE-unlocking, but post rooting. I noticed nobody mentioned it on XDA or here so I wanted to throw it out there for other to test and confirm results.

    I honestly prefer staying away from app cpu clockers, just like you stated, its just optimal. Since at the time the kernel was stock, we were limited. I've already moved on to the Ziggy kernel, and tweaking the clock speed up to 1800mhz and undervolting to stock voltage levels of the 1500mhz setting :)

    So far im stabled as hell! Thanks for the heads up on System Tuner, i may actually pay for the full version as another great tweak it has is the SD Card Cache adjustment which nobody has yet to point out in its own thread. It also has the startup disabler... the only thing its missing is the trigger point startup adjustments (I guess thats my validation for paying for AutoStarts).
    BlueBiker and EarlyMon like this.
  12. EarlyMon

    EarlyMon The PearlyMon Moderator

    Yeah, wasn't trying to disrespect your efforts, just thought this would be a popular thread into the future and so wanted to lay out some current info moving forward from the perm-root point.

    I've been using System Tuner, watching it evolve. Really great stuff. :)
  13. BlueBiker

    BlueBiker Well-Known Member

    I've had QSIP installed for a couple weeks but didn't think it was reporting both cores & clocks on the Rez. Just tried it while rapidly firing up and switching between apps, and sure enough it does. Nice!
    EarlyMon likes this.
  14. IzelTokatl

    IzelTokatl Well-Known Member

    I found out System Panel does report both cores working. Apparently the 2nd core only comes on in extremely high loads. There is a tweak if your using ziggy's kernel that forces both cores to be used at all times instead of at peak load.
  15. EarlyMon

    EarlyMon The PearlyMon Moderator

    I have a picture above of System Panel showing both cores working. What it doesn't do is show both clock speeds.
  16. johnciv6

    johnciv6 Member

    Old thread, but id like to add I get considerably more battery life. Unplugged at 7 this morning, it's now 11 and I have 37% left. I also spend a good chunk of the day not in service. Which I believe hurts battery while searching??
  17. johnciv6

    johnciv6 Member

    Just an update, Im at 16% 24 hours later.


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  18. Wildxmo

    Wildxmo New Member

    Nice! What settings are you using?

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