Android CPU Governors, Hotplugging drivers, GPU governors and I/O Schedulers - EXPLAINED!


psydex » , , , , , , , , , ,

 (Trouble viewing? Click here)


Recommended apps for manipulating kernel values:
1. Kernel Adiutor (Free to change governor and tune variables)
2. Kernel Adiutor-Mod (Free to change governor and tune variables)
3. Compatible kernel managers (e.g Stweaks, Synapse, UKM, etc.)



This pages includes:


- Descriptions
- CPU governors
- Hotplugging drivers
- GPU governors
- Categorizations
- Recommendations
- Graphs
- Tunables



What is a CPU governor?


A CPU governor in Android controls how the CPU raises and lowers its frequency in response to the demands the user is placing on their device. Governors are especially important in smartphones and tablets because they have a large impact on the apparent fluidity of the interface and the battery life of the device over a charge.

NOTE: You cannot change your CPU governor unless your phone is rooted and you have a ROM or app that lets you make a change. Also, different kernels (the intermediary software between your phone's hardware and the operating system) offer different sets of governors.




Available CPU governors:


  1. OnDemand
  2. OnDemandX
  3. Performance
  4. Powersave
  5. Conservative
  6. Userspace
  7. Min Max
  8. Interactive
  9. InteractiveX
  10. Smartass
  11. SmartassV2
  12. Scary
  13. Lagfree
  14. Smoothass
  15. Brazilianwax
  16. SavageZen
  17. Lazy
  18. Lionheart
  19. LionheartX
  20. Intellidemand
  21. Hotplug
  22. Badass
  23. Wheatley
  24. Lulzactive
  25. PegasusQ\PegasusD
  26. HotplugX
  27. Abyssplug
  28. MSM DCVS
  29. Intelliactive
  30. Adaptive
  31. Nightmare
  32. ZZmoove
  33. Sleepy
  34. Hyper 
  35. SmartassH3
  36. SLP
  37. NeoX
  38. ZZmanX
  39. OndemandPlus
  40. Dynamic Interactive (DynInteractive)
  41. Smartmax
  42. Ktoonservative\KtoonservativeQ
  43. Performance may cry (PMC)
  44. Dance Dance
  45. AbyssPlugv2
  46. IntelliMM
  47. InteractivePro
  48. Slim
  49. Ondemand EPS  
  50. Smartmax EPS
  51. Uberdemand
  52. Yankactive
  53. Impulse
  54. Bacon
  55. Optimax
  56. Preservative
  57. Touchdemand
  58. ElementalX
  59. Bioshock
  60. Blu_active
  61. Umbrella_core
  62. ConservativeX
  63. Hyrdxq
  64. DevilQ
  65. Yankasusq
  66. Darkness
  67. Alucard
  68. Hellsactive
  69. Ragingmolasses
  70. Virtuous
  71. Sakuractive
  72. InteractiveX v2
  73. Alessa
  74. GallimaufryX
  75. AggressiveX
  76. Tripndroid
  77. Wrexy
  78. Xperience
  79. Stockdemand
  80. Zeneractive
  81. InteractiveB
  82. Aggressive
  83. IntellidemandV2
  84. Boostactive
  85. Wave
  86. Barry-Allen
  87. Arteractive
  88. Precognition (PrecoGOV)
  89. Mythx_plug
  90. PegasusQPlus
  91. Yankdemand
  92. HyperX
  93. Despair
  94. Electroactive
  95. Electrodemand
  96. Lionfish
  97. Interextrem
  98. Cafactive
  99. Lightning
  100. ThunderX
  101. sched-DVFS
  102. Intel
  103. Frankenstein
  104. Cyan  
  105. TheSSJactive 
  106. Chill 
  107. sprdemand 


Things to look out for in a CPU governor:


There are many CPU governors available on android, but there are some important things people should look out for before selecting their new governor:

- Speed - The more the better!!!! Usually having lots of speed equates to lower battery life, so it is best to balance this out.
- Battery life - More of this means more battery life!!! Being very battery friendly usually means less speed (or sometimes smoothness), so it's best to balance this out. 
- Stability - Some governors are plain unstable and some are rock solid. Of course people would want a stable CPU governor!!!
- Smoothness (or Fluidity) - This is not the same as speed, a governor can be fast but it doesn't mean it is smooth. A way to test this is to scroll down/up pages or open and close apps. Of course, more smoothness = awesome phone experience


Descriptions:


Cpu governors

1: OnDemand:

Ondemand is one of the original and oldest governors available on the linux kernel.  When the load placed on your CPU reaches the set threshold, the governor will quickly ramp up to the maximum CPU frequency. It has excellent fluidity because of this high-frequency bias, but it can also have a relatively negative effect on battery life versus other governors. OnDemand was commonly chosen by smartphone manufacturers in the past because it is well-tested and reliable, but it is outdated now and is being replaced by Google's Interactive governor. 

2: OndemandX:

Basically an ondemand with suspend/wake profiles. No further optimization was done to Ondemand to keep it close to source as possible. 

3: Performance:

The performance governor locks the phone's CPU at maximum frequency. 

4: Powersave:

The opposite of the Performance governor, the Powersave governor locks the CPU frequency at the lowest frequency set by the user.

5: Conservative:

This governor biases the phone to prefer the lowest possible clockspeed as often as possible. In other words, a larger and more persistent load must be placed on the CPU before the conservative governor will be prompted to raise the CPU clockspeed. Depending on how the developer has implemented this governor, and the minimum clockspeed chosen by the user, the conservative governor can introduce choppy performance. On the other hand, it can be good for battery life.

The Conservative Governor is also frequently described as a "slow OnDemand". The original and unmodified conservative is slow and inefficient. Newer and modified versions of conservative (from some kernels) are much more responsive and are better all around for almost any use. 

6: Userspace:


This governor, exceptionally rare for the world of mobile devices, allows any program executed by the user to set the CPU's operating frequency. This governor is more common amongst servers or desktop PCs where an application (like a power profile app) needs privileges to set the CPU clockspeed.

7: Min Max


Min Max is a governor that makes use of only min & maximum frequency based on workload. no intermediate frequencies are used! 

8: Interactive:


Interactive scales the clockspeed over the course of a timer set by the kernel developer (or user). In other words, if an application demands a ramp to maximum clockspeed (by placing 100% load on the CPU), a user can execute another task before the governor starts reducing CPU frequency. Because of this timer, Interactive is also better prepared to utilize intermediate clockspeeds that fall between the minimum and maximum CPU frequencies.
 It is significantly more responsive than OnDemand, because it's faster at scaling to maximum frequency.

Interactive also makes the assumption that a user turning the screen on will shortly be followed by the user interacting with some application on their device. Because of this, screen on triggers a ramp to maximum clockspeed, followed by the timer behavior described above. 



Interactive is the default governor of choice for today's smartphone and tablet manufacturers.


9: InteractiveX:

Created by kernel developer "Imoseyon," the InteractiveX governor is based heavily on the Interactive governor, enhanced with tuned timer parameters to better balance battery vs. performance. The InteractiveX governor's defining feature, however, is that it locks the CPU frequency to the user's lowest defined speed when the screen is off.

10: Smartass


Based on interactive, performance is on par with the “old” minmax and smartass is a bit more responsive. Battery life is hard to quantify precisely but it does spend much more time at the lower frequencies.

Smartass will also cap the max frequency when sleeping to 352Mhz (or if your min frequency is higher than 352 it will cap it to your min frequency).


This governor will slowly ramp down frequency when the screen is off and it could also let the frequency go to low making your phone unusable (if min frequency is not checked).  


11: SmartassV2:

Version 2 of the original smartass governor from Erasmux. The governor aim for an "ideal frequency", and ramp up more aggressively towards this freq and less aggressive after. It uses different ideal frequencies for screen on and screen off, namely awake_ideal_freq and sleep_ideal_freq. This governor scales down CPU very fast (to hit sleep_ideal_freq soon) while screen is off and scales up rapidly to awake_ideal_freq when screen is on. There's no upper limit for frequency while screen is off (unlike Smartass). So the entire frequency range is available for the governor to use during screen-on and screen-off state. The motto of this governor is a balance between performance and battery. 

12: Scary


A new governor wrote based on conservative with some smartass features, it scales accordingly to conservatives laws. So it will start from the bottom, take a load sample, if it's above the up threshold, ramp up only one speed at a time, and ramp down one at a time. It will automatically cap the off screen speeds to whatever the kernel developer sets it too and will still scale accordingly to conservatives laws. So it spends most of its time at lower frequencies. The goal of this is to get the best battery life with decent performance. 

13: Lagfree:


Lagfree is similar to ondemand. Main difference is it's optimization to become more battery friendly. Frequency is gracefully decreased and increased, unlike ondemand which jumps to 100% too often. Lagfree does not skip any frequency step while scaling up or down. Remember that if there's a requirement for sudden burst of power, lagfree can not satisfy that since it has to raise cpu through each higher frequency step from current. Some users report that video playback using lagfree stutters a little. Depending on the implementation, lagfree can also be performance oriented at the cost of battery life. 

14: Smoothass:


The same as the Smartass “governor” But MUCH more aggressive & across the board. 

15: Brazilianwax:


Similar to smartassV2. More aggressive ramping, so more performance, less battery

16: SavagedZen:


Another smartassV2 based governor. Achieves good balance between performance & battery as compared to brazilianwax.

17: Lazy:

This governor from Ezekeel is basically an ondemand with an additional parameter min_time_state to specify the minimum time CPU stays on a frequency before scaling up/down. The Idea here is to eliminate any instabilities caused by fast frequency switching by ondemand. Lazy governor polls more often than ondemand, but changes frequency only after completing min_time_state on a step overriding sampling interval. Lazy also has a screenoff_maxfreq parameter which when enabled will cause the governor to always select the maximum frequency while the screen is off.

18: Lionheart:


Lionheart is a conservative-based governor which is based on samsung's update3 source.
The tunables (such as the thresholds and sampling rate) were changed so the governor behaves more like the performance one, at the cost of battery as the scaling is very aggressive. 

19: LionheartX


LionheartX is based on Lionheart but has a few changes on the tunables and features a suspend profile based on Smartass governor.

20: Intellidemand:


Intellidemand aka Intelligent Ondemand from Faux is yet another governor that's based on ondemand. The original intellidemand behaves differently according to GPU usage. When GPU is really busy (gaming, maps, benchmarking, etc) intellidemand behaves like ondemand. When GPU is 'idling' (or moderately busy), intellidemand limits max frequency to a step depending on frequencies available in your device/kernel for saving battery. This is called browsing mode. 

To sum up, this is an intelligent ondemand that enters browsing mode to limit max frequency when GPU is idling, and (exits browsing mode) by behaving like ondemand when GPU is busy; to deliver performance for gaming and such. Intellidemand does not jump to highest frequency when screen is off. Faux no longer recommends intellidemand and believes that intellidemand users should switch to intelliactive for better optimizations and performance. 

21: Hotplug:


The Hotplug governor performs very similarly to the OnDemand governor, with the added benefit of being more precise about how it steps down through the kernel's frequency table as the governor measures the user's CPU load. However, the Hotplug governor's defining feature is its ability to turn unused CPU cores off during periods of low CPU utilization. This is known as "hotplugging."

22: BadAss:


Badass removes all of this "fast peaking" to the max frequency. To trigger a frequency increase, the system must run a bit with high load, then the frequency is bumped. If that is still not enough the governor gives you full throttle. (this transition should not take longer than 1-2 seconds, depending on the load your system is experiencing)
Badass will also take the gpu load into consideration. If the gpu is moderately busy it will bypass the above check and clock the cpu to max frequency. If the gpu is crushed under load, badass will lift the restrictions to the cpu.

23: Wheatley:

This governor is build on “ondemand” but increases the C4 (the sleep state) state time of the CPU and doing so trying to save juice. So the results show that Wheatley works as intended and ensures that the C4 state is used whenever the task allows a proper efficient usage of the C4 state. For more demanding tasks which cause a large number of wakeups and prevent the efficient usage of the C4 state, the governor resorts to the next best power saving mechanism and scales down the frequency. So with the new highly-flexible Wheatley governor one can have the best of both worlds. Obviously, this governor is only available on multi-core devices.

Wheatley is a more performance orientated governor as it scales more aggressively than ondemand and sticks with higher frequencies. 

24:Lulzactive\LulzactiveQ:


It's based on Interactive & Smartass governors.

Old Version: When workload is greater than or equal to 60%, the governor scales up CPU to next higher step. When workload is less than 60%, governor scales down CPU to next lower step. When screen is off, frequency is locked to global scaling minimum frequency.

New Version: Three more user configurable parameters: inc_cpu_load, pump_up_step, pump_down_step. Unlike older version, this one gives more control for the user. We can set the threshold at which governor decides to scale up/down. We can also set number of frequency steps to be skipped while polling up and down.
When workload greater than or equal to inc_cpu_load, governor scales CPU pump_up_step steps up. When workload is less than inc_cpu_load, governor scales CPU down pump_down_step steps down.

25: Pegasusq/Pegasusd

The Pegasusq / d is a multi-core based on the Ondemand governor and governor with integrated hot-plugging. It is quite stable and has the same battery life as ondemand. Ongoing processes in the queue, we know that multiple processes can run simultaneously on. These processes are active in an array, which is a field called "Run Queue" queue that is ongoing, with their priority values ​​arranged (priority will be used by the task scheduler, which then decides which process to run next).

To ensure that each process has its fair share of resources, each will run for a certain period and will eventually stop and then again placed in the queue until it is your turn again. If a program is terminated, so that others can run the program with the highest priority in the current queue is executed.

26: Hotplugx

It's a modified version of Hotplug and optimized for the suspension in off-screen

27: AbyssPlug


It's a Governor derived from hotplug, it works the same way, but with the changes in savings for more battery life.

28: MSM DCVS

A very efficient and wide range of Dynamic Clock and Voltage Scaling (DCVS) which addresses usage models from active standby to mid and high level processing requirements. It makes the phone's CPU smoothly scale from low power, from low leakage mode to blazingly fast performance.Only to be used by Qualcomm CPUs.

MSM is the prefix for the SOC (MSM8960) and DCVS is Dynamic Clock and Voltage Scaling. Makes sense, MSM-DCVS

29: IntelliActive


Based off Google's Interactive governor with the following enhancements:

1. self-boost capability from input drivers (no need for PowerHAL assist)
2. two phase scheduling (idle/busy phases to prevent from jumping directly to max freq
3. Checks for offline cpus and short circuits some unnecessary checks to improve code execution paths. Therefore, it avoids CPU hotplugging. 

Created by Faux

30: Adaptive

This driver adds a dynamic cpufreq policy governor designed for latency-sensitive workloads and also for demanding performance.
This governor attempts to reduce the latency of clock so that the system is more responsive to interactive workloads in lowest steady-state but to reduce power consumption in middle operation level, level up will be done in step by step to prohibit system from going to
max operation level.

31: Nightmare 

A PegasusQ modified, less aggressive and more stable. A good compromise between performance and battery. In addition to the SoD is a prevention because it usually does not hotplug.

32: ZZmoove


The ZZmoove Governor by ZaneZam is optimized for low power consumption when the screen off, with particular attention to the limitation of consumption applications in the background with the screen off, such as listening to music. The unique feature with ZZmoove is that it has predefined profiles and allows profile switching. This governor is still a WIP as the developer is constantly giving updates! Here are the available profiles:

  1. for Default (set governor defaults)
  2. for Yank Battery -> old untouched setting (a very good battery/performance balanced setting DEV-NOTE: highly recommended!)
  3. for Yank Battery Extreme -> old untouched setting (like yank battery but focus on battery saving)
  4. for ZaneZam Battery -> old untouched setting (a more 'harsh' setting strictly focused on battery saving DEV-NOTE: might give some lags!)
  5. for ZaneZam Battery Plus -> NEW! reworked 'faster' battery setting (DEV-NOTE: recommended too!  )
  6. for ZaneZam Optimized -> old untouched setting (balanced setting with no focus in any direction DEV-NOTE: relict from back in the days, even though some people still like it!)
  7. for ZaneZam Moderate -> NEW! setting based on 'zzopt' which has mainly (but not strictly only!) 2 cores online
  8. for ZaneZam Performance -> old untouched setting (all you can get from zzmoove in terms of performance but still has the fast down scaling/hotplugging behaving)
  9. for ZaneZam InZane -> NEW! based on performance with new auto fast scaling active. a new experience!
  10. for ZaneZam Gaming -> NEW! based on performance with new scaling block enabled to avoid cpu overheating during gameplay
  11. for ZaneZam Relax -> NEW! based on moderate (except hotplug settings) with relaxed sleep settings
    (since version 0.9 beta4: cpu temperature threshold of 65°C enabled if exynos4 cpu temperature reading support was compiled with the governor)

33: Sleepy

The Sleepy (formerly known as Solo) is an attempt to strike a balance between performance and battery power to create. It is based on Ondemand. It includes some tweaks like the Down_sampling variable and other features that set by the user through the sysfs of "echo" call. Sleepy is quite similar to Ondemandx.


34: Hyper

The Hyper (formerly known as kenobi) is an aggressive smart and smooth governor based on the Ondemand and is equipped with several features of Ondemandx suspend profiles. It also has the fast_start deep_sleep variable and detection features. In addition, the maximum frequency is in suspend mode 500Mhz or whatever the kernel devel. This is a more smoothness oriented governor which means that it is good for performance, without sacrificing much battery life.


35: SmartassH3

Based on SmartassV2 with parameters tuned by H3ROS. It has been tuned to have more efficient frequency scaling (not ramping too high when not needed) which this could potentially result in better battery life.

36: SLP 

It is a mix of pegasusq and ondemand. Therefore, it has a balance between battery savings and performance.

37: NeoX 

An optimized version of the pegasusq governor but with some extra tweaks for better performance. This means slightly more battery drainage than the original PegasusQ but it is still a balanced governor. 

38. ZZmanx

ZZmanx is exactly the same as ZZmove, but it has been renamed because DorimanX made it into his own version (possibly better performance) . However, it still suffers from below average gaming performance. (Refer to ZZmoove description for guide on profiles)


39. OnDemandPlus

Ondemandplus is an ondemand and interactive-based governor that has additional power-saving capabilities while maintaining very snappy performance. While the interactive governor provides a modern and sleek framework, the scaling logic has been been re-written completely. Reports have found that users find ondemandplus as a more battery friendly governor. In ondemandplus, the downscaling behavior from ondemand is only very slightly modified. However, the upscaling has been modified to not scale up to maximum frequency immediately.


40. Dynamic Interactive (DynInteractive)

This governor dynamically adjusts itself according to load. That means it's settings are dynamic (always changing) and not static (not changing). Dyninteractive still obtains the same great balance between battery life and performance found in the original interactive governor and improves it even further. This is not the same as the original interactive governor because of this unique behavior. 

41. Smartmax

Smartmax is a mix between ondemand and smartassv2. It behaves mostly like smartass with the concept of an "ideal" frequency. By default this is configured for battery saving, so this is NOT a gaming or benchmark governor! Additionally, to make it "snappy", smartmax has "touch poke". So input events from the touchscreen will boost the cpu for a specific time to a specific frequency. Developed by XDA user Maxwen.

42. Ktoonservative\KtoonservativeQ

A combination of ondemand and conservative. Ktoonservative contains a hotplugging variable which determines when the second core comes online. The governor shuts the core off when it returns to the second lowest frequency thus giving us a handle on the second performance factor in our CPUs behavior. 



43. Performance may cry (PMC)

A governor based on Smartmax except it's heavily tweaked for better and maximum battery life. This is not a gaming governor!

44. Dance Dance

Based on conservative with some smartass features, it scales accordingly to conservatives laws. So it will start from the bottom, take a load sample, if it's above the upthreshold, ramp up only one speed at a time, and ramp down one at a time. It will automatically cap the off screen speeds to 245Mhz, and if your min freq is higher than 245mhz, it will reset the min to 120mhz while screen is off and restore it upon screen awakening, and still scale accordingly to conservatives laws. So it spends most of its time at lower frequencies. The goal of this is to get the best battery life with decent performance. It is a performance focused governor but also blends with some battery savings. 

45. AbyssPlugv2

AbyssPlugv2 is a rewrite of the original CPU governor. It also fixes the problem where the governor is set only for the first core, but now governs all cores right from whatever utility you use. There have been comments on the lack of stability with this governor. 

46. IntelliMM

A rewrite of the old Min Max governor and has 3 cpu states: Idle, UI and Max. Intelliminmax (intellimm) governor is designed to work with the newer SOCs with fixed voltage rails (ie MSM8974+ SOCs). It is designed to work within those fixed voltage ranges in order to maximize battery performance while creating a smooth UI operations. It is battery friendly and spends most of the time at lower frequencies. 

47. Interactive Pro

A newer (modified) version of interactive which is optimized for devices such as the One Plus One. It is a more efficient than the original Interactive because it continuously re-evaluates the load of each CPU therefore allowing the CPU to scale efficiently.

48. Slim

A new governor from the cm branch and the slimrom project. This is a performance optimized governor and has been tuned a lot for newer devices such as the One Plus One. 

49. Ondemand EPS

A modified version of Ondemand and is optimized for newer devices. It is based on the Semaphore Kernel's Ondemand which is more optimized for battery life. The EPS at the end stands for Extreme power savings so this governor is biased to power savings!

50. Smartmax EPS

This governor is based on Smartmax but is optimized for 'Extreme Power Saving' (hence the EPS suffix). This means it uses less battery than the original Smartmax so it is not a very good gaming governor (again!) This is only found on newer devices. 
51. Uberdemand

Uberdemand is Ondemand with 2-phase feature meaning it has a soft cap at 1728 MHz so your cpu won't always go directly to max, made by Chet Kener.

52. Yankactive

A slightly modified interactive based governor by Yank555.lu. It has battery tweaks added onto it so expect better battery life! Based on user reports, this governor behaves more battery friendly than the original interactive governor without sacrificing performance. 
53. Impulse

 An improved version of interactive modified by neobuddy89. Impulse aims to have a balance between battery and performance just like interactive but has some tweaks to save battery. 

54. Bacon

This is nothing but polished interactive governor branded as "bacon" since it was adapted from bacon device thanks to neobuddy89. Most of the tweaks are for performance/latency improvements

55. Optimax governor

This is based on ONDEMAND, like almost all governors that have arisen from XDA. It contains some enhancements from LG, particularly to freq boost handling so it will boost to a set level, almost like HTC's governor. It has different tunables to the HTC governor but it behaves pretty similar, the tunables it comes with default are a bit more conservative.
It originates from Cl3kener's Uber kernel for Nexus 5, where it has quite a reputation for battery life

56. Preservative governor

This is based on the idea that the CPU will consume a lot of power when it changes frequency. It is based on the conservative governor. The idea is that it will stay at the step specified (702MHz selected by the creator Bedalus) unless needed. You will notice it will hover around 702 a lot, and not go above too much, and only to min freq when NOTHING is happening at all. This is most beneficial when you are doing something like reading; the screen is static or playing light games that won't need boosting any more
The governor comes from Moob kernel for nexus 4

57. Touchdemand

Touchdemand is based on the ondemand cpu governor but has been modified for the Tegra 3 chip (tablet only) and has additional tweaks for touchscreen responsiveness.

58. ElementalX

The ElementalX CPU governor has been specifically designed and tuned to get the best balance between battery life and performance. By default, it is more conservative than Ondemand. During routine usage, the CPU frequency does not ramp up very often. If gboost is enabled, during gaming or any other graphics intensive situation, the CPU frequencies boost much easier in order to maintain maximum performance. There is also a built in input boost. 

59. Bioshock

Not the game, but rather the CPU governor developed by Jamison904A mix of ConservativeX and Lionheart. Good balance between battery savings and performance. 

60. Blu_active

A new cpu governor developed by eng.stk (featured in his Code_Blue kernels) based on interactive with upstream caf patches and ondemand governor bits too. This governor is mainly focused on performance like the other things the developer creates but it is also well balanced for gaming and general usage.
61. Umbrella_core

A new cpu governor by twisedumbrella based on interactive that is focused on battery life and not performance. It will still ramp up to a set frequency but will not stay at high frequencies for long. This governor tends to stay in high-mid range frequencies during screen_off. 

62. ConservativeX

Also developed by Imoseyon (feat. briefly in the Lean Kernel for Galaxy Nexus), the ConservativeX governor behaves like the Conservative governor with the added benefit of locking the CPU frequency to the lowest interval when the screen is off. This governor may additionally perform hotplugging on CPU1, but there is no documentation to confirm that suspicion at this time.

63. HydrxQ

Simply a lulzactiveq governor with tweaks to performance (thanks to tegrak). This means more performance and less battery life. 

64. DevilQ

An aggressive pegasusq governor which keeps the hotplugging at max 2 cpu cores to offline). This is pretty much a more optimized pegasusq for phone's with quad core processors.

65. YankasusQ

Yankasusq is another modified pegasusq but with including screen off freq tunable and some other modifications as well. The difference between PegasusQ and YanksusQ is that it doesn't ramp too aggressively when screen turns on (less battery drainage).

66. Darkness

It's based on nightmare but more simple and fast, basic configs but very complex structure. It is an updated version of the nightmare gov, so far it is quite stable in tests

67. Alucard

A favourite choice and one of the original governors that Alucard_24 made. Alucard is based on ondemand but has been heavily tweaked to bring better battery life and performance. It has been known to be battery friendly without sacrificing much performance.

68. Hellsactive

A heavily modified intelliactive governor by hellsgod that has been tweaked to improve battery life. Hellsactive is less aggressive compared to intelliactive so the battery life will be more like the original interactive. 

69. Ragingmolasses

Besides a gov with an awesome name its a mash up of conservative and ondemand and scales based on load with few tunables. Its meant to be simple, fast, and efficient at keeping the frequency away from the max clock unless it is absolutely needed. it includes gboost for better gaming.

70. Virtuous


It sets your max cpu for wake and sleep and changes the governor when your device is awake or asleep. It saves battery by lowering cpu frequencies while the device sleeps, when it awakes it automatically speeds it up again. Or alternately you can set the cpu. It is based on smartassV2(It uses 2 governors, one for sleep and other for awake)

71. Sakuractive

An aggressive hybrid of ondemand and hotplug, which means it will scale like ondemand, except a little more aggressive. But also acts like hotplug due to it shutting off a core.

72. InteractiveX v2

Also developed by Imoseyon (feat. in the Lean Kernel for Galaxy Nexus), the InteractiveX V2 governor behaves like InteractiveX, and additionally forces CPU1 into a hotplug state when the screen is off.

73. Alessa

A less aggressive and more stable ondemand modified by TeamMex. A good compromise between performance and battery. It can be used with the complementary hotplug governor. Please note that this governor is still a WIP! 

74. GallimaufryX

A modded ondemand that is a 2-stage ondemand governor with speed tweaks. It includes imoseyon's screen-off hotplugging code.

75. AggressiveX

A modded conservative governor but with lots of tweaks to increase snappiness while saving power. It also includes imoseyon's screen-off hotplugging code.

76. Tripndroid

Instead of the I/O scheduler, this is a CPU governor based on ondemand with extra tweaks for performance

77. Wrexy

Wrexy is a conservative based governor. Its similiar to the Lionheart gov. It tends to stay out of higher frequencies to favor lower frequencies but performance is not much affected. 

78. Xperience 

A tweaked smartassv2 for better performance and smoothness. Created by TeamMex. 

79. Stockdemand

A heavily modified ondemand for better performance and battery life. It is still a well balanced governor and it is designed for everyday use.

80. Zeneractive

This new "zeneractive" governor is based on interactive. It handles frequency scaling the exact same as interactive and has the same tunables as interactive for frequency scaling. However, on zeneractive all of the new hotplugging code that's in there is "from scratch." 

81. InteractiveB

An interactive based governor with a more balance battery life/performance profile

82. Aggressive

Like Lionheart, it is based on conservative, but even more aggressive

83. Intellidemandv2

Much like its predecessor, intellidemandv2 is an intelligent ondemand with browsing detection and scales based on GPU loading. It has been optimized for specific devices and has better battery life and performance. 

84. Boostactive

Based on Interactive but with cpu frequency boosting capabilities. This is performance oriented governor. 

85. Wave

Based on Conservative with some tweaks for speed and battery. This governor was created by zparallax. 


86. Barry-Allen

It's based on interactive. The governor is supposed to be more battery friendly and at the same have good performance.

87. Arteractive

It is an interactive CPU governor port from newer source code. It has more optimizations for Snapdragon 80x processors.

88. Precognition (PrecoGOV)

PrecoGOV takes over and dynamically adapts to your usage pattern. To achieve such goal, PrecoGOV manages the frequency, idle & sleep patterns, hotplugging, temperature per core and even gpu and tries to help the scheduler as best as it can, all while taking into account battery and thermal constraints.


89. Mythx_plug

It's based on an improved Interactive governor and has been modified to scale up slower and scale down faster. It is a battery friendly governor. 


90. PegasusQPlus

PegasusQPlus is a heavily tweaked PegasusQ governor, which has been implemented by AndreiLux in his Perseus kernel. PegasusQPlus should have a better balance between performance and battery usage.


91. Yankdemand

Full stock (JB) ondemand governor with changed default tunable values aimed at lower battery consumption


92. HyperX

A tweaked interactive based governor for performance.

93. Despair

It is a tweaked conservative governor with a couple extra values exposed, it tends to be a bit more conservative with battery than the conservative governor by default. Developed by DespairFactor.

94. Electroactive

The Electroactive CPU governor has been created to get some of the best balances between battery life and performance that you will see on a device. This governor is the replacement over the original electrodemand governor, being much more battery friendly with much smoother transitions compared to the original. It is a hybrid class governor, using a unique way to merge the best of both interactive and ondemand. It includes some extra additions and enhancements to be more battery saving than interactive governor and some boost tunes and additions that allow better power management and performance in games as well as better power saving when in normal use. CPU boost, graphics boost, fast_start deep_sleep and detection features are built in as well as 300 MHz clock speed in suspend. 

95. Electrodemand

Based on the ondemand cpu governor, this is the older governor that was used in the electroactive kernel which uses the same tunables found in the original ondemand governor. 

96. Lionfish

The Lionfish governor combines traits of the conservative, ondemand, and interactive governors. It is designed to maximize battery life without noticeably impacting performance. It responds quickly to heavy loads (similar to ondemand and interactive) while staying within the region of optimal CPU performance per watt. With moderate loads, it periodically votes to raise, maintain, or decrease the frequency. When there are enough votes to change the frequency, it is ramped up and down gradually. The voting mechanism reduces frequency jitter compared to ondemand and conservative. squid2's testing had found that this governor uses moderate frequencies (where efficiency is optimal) more effectively than interactive, ondemand, and conservative. This improved frequency distribution results in a moderate reduction in CPU power consumption while maintaining responsiveness comparable to the interactive governor.

97. Interextrem

A tweaked interactive governor by thehacker911. It is found in hacker kernel s6, where it has been tuned for better performance while still maintaining good battery life. 

98. Cafactive

Found in arter97's kernels, cafactive is the qualcomm optimized version of interactive from CodeAurora. This version promises to bring greatly enhanced performance over samsung's own version of interactive (benchmarks have shown a increase in performance scores), however it may be unstable on some devices and may cause some performance issues under normal and heavy operation. 

99. Lightning

Lightning is modified darkness gov made by @HridayHS

100. ThunderX

ThunderX is a power saving CPU governor based on SmartAssv2 optimized for Mediatek SoCs. 


101. sched-DVFS

A governor by Linaro and ARM that promises to provide better battery life while also being easy to configure. Unlike normal CPU governors that rely on a sampling-based approach to consider cpu time, sched-DVFS uses scheduler task utilization tracking which provides smoother scaling and better response to changing CPU load. Only found on Energy Aware Scheduling (EAS) kernels. According to some reports, energy savings differ between devices and may cause instabilities 


102. Intel

It's an interactive based governor that is optimized for Intel devices. It is thought to be more battery friendly than interactive while still having good performance. Found only on intel based SOCs.

103. Frankenstein

Based on interactive with hotplugging, it is a performance oriented governor but aims to save battery when screen is off. However, it may be unstable on some devices. Found only on intel based SOCs.

104. Cyan

Cyan is an interactive based CPU governor intended for heavy gaming and processes. It was originally developed for the i9500, but is now found in kernels for devices with intel SOCs.

105. TheSSJactive

TheSSJactive is based on yankactive but with the addition of hotplugging support for intel SOCs. It is known to be a battery friendly governor. 


106. Chill

A conservative based governor by frap129 (Electron kernel). It's aims to provide more aggressive battery savings while screen is off. 


107. sprdemand

This governor is exactly the same as ondemand but with added functionality to offline auxiliary CPUs when screen is off or due to thermal constraints. 

Hotplugging drivers:

mpdecision: Qualcomm's default hotplugging driver. One of the most widely used hotplug drivers in all android devices.


msm_hotplug: Great battery life, a custom qualcomm based hotplugging driver by myflux. It is a popular choice for many users.

intelliplug: Great balance between battery life and performance. It is also a popular hotplug driver from faux123.

Alucard: A great hotplugging driver by Alucard. It is known to be very battery friendly on devices.

Kt Auto Hotplug: A great hotplug driver by Ktoonsez. Pretty much a smarter mpdecision that has been optimized for quad-core devices.

Mako Hotplug: A new popular hotplugging driver found in Francokernel. This is a highly configurable driver that can be configured to use dual core for light-loads and quad-core for heavy loads.

Zen Decision: ZEN only onlines all cores when screen is on, it also takes thermal events into account and wont online any core back, if you're under 15% battery, or currently have a thermal event because of heat. So in the end it isn't a "real" hotplug driver, because it doesnt have any code for active hot plugging in it. That means you can't change its behavior.

Bricked Hotplug: Conservative hotplug driver by @showp1984. It is based on mpdecision but has been optimized for better balance between battery life and performance.

msm_sleeper: The main feature with this hotplug is that you can customize the screen off frequency. Two cores are always on, the third and fourth are independent and come online if needed. By default, if the load is over 80 for 400ms another core comes online. The third and/or fourth cores stay online as long as the load demands it or for a minimum of one second. While the screen is off, it goes down to a single core. Created by flar2.

Autosmp: A highly-efficient hotplug driver by @mrg666, works in-sync with the CPU governor to enable off-line cpu cores when the the CPU frequency reaches a high threshold and still more compute power is needed. Therefore, touch boost bloat is removed. 

Thunderplug: A matured load-based hotplug driver with many tunables written from ground up by varun.chitre15. This hotplug is optimized for octa-core devices and also has support for 64bit CPUs.

Blu_plug: Dynamic hotplug from eng.stk's shamu kernel with screenoff battery saving. 

cpuquiet: A hotplug driver by NVidia and ported to Snapdragon by maxwen. Originally made for NVidia tegra SOCs. It has a set of governors which keep the CPU running at optimal frequencies for battery and performance.


Fast hotplug:  A hotplug driver from pec0ra's abricot kernel. It aims to be as lightweight as possible while also being highly customizable. However, it is still a WIP as it is known to have some stability issues. 

Hima hotplug: An optimized hotplug driver based on intelliplug for big.LITTLE architecture. Found on chadouming's HTC One (M9) kernel, it takes advantage of the big and LITTLE CPU cores in order to provide 'butter smooth' performance.  

State Helper: A hotplug driver by @neobuddy89 designed with the Nexus 6 in mind. It is highly configurable giving the user control over what CPUs to online based on what battery threshold levels have been set. Another feature that sets state helper apart from other hotplug methods is that it respects the thermal driver. 


 

Custom kernels may have their own hotplugging drivers but they are usually based on these ones. 


For qualcomm devices:

Battery life:

- mpdecision
- Mako Hotplug
- Intelliplug
- Alucard


For performance:

- Kt Auto Hotplug
- mpdecision


For balanced:

- Bricked Hotplug
- Mako Hotplug
- Intelliplug
- mpdecision


GPU governors


Simple: It's a new governor for the gpu frequency scaling. It will allow a more fine grained control over how the gpu scales up and down then the previous ones. Depending how you tune it, it can be better for battery life or performance.


Ondemand: Much like the CPU governor, Ondemand will ramp up the frequency when a load is detected. A good balance between performance and battery savings. This is a widely used governor in qualcomm devices.


MSM-Adreno: The default GPU governor used by qualcomm for their adreno GPUs. It is more performance orientated than ondemand therefore it gives better performance in games but less battery life. It is still a balanced governor for everyday usage.


Performance: As the name suggests, this keeps your GPU running at the max frequency. This is a governor if you want the best possible experience in games but you don't care about your battery life.


Powersave: Like the CPU governor, this keeps your GPU running at the lowest possible frequency. Best battery life, extreme lag in games.


Adreno Idler: It is an idling algorithm, an efficient workaround for msm-adreno-tz's overheads. Main goal is to lower the power consumptions while maintaining high-performance. Since msm-adreno-tz tends to *not* use the lowest frequency even on idle, Adreno idler replaces msm-adreno-tz's algorithm when it comes to calculating idle frequency(mostly by ondemand's method). The higher frequencies are not touched with this algorithm, so high-demanding games will (most likely) not suffer from worsened performance.


Userspace: This governor basically allows the user is able to set a desired frequency for the GPU to run at.


cpubw_hwmon: A hardware (HW) monitor based governor that attempts to determine bandwidth needed by CPU and other hardware. This is a unique GPU governor that is highly customisable, however it is known to be unstable on some devices.


MSM Cpufreq: The MSM CPUfreq governor determines the CPU to DDR bandwidth vote based on the current CPU frequency of all the active CPUs. In other words, this governor scales based on CPU usage which could mean more performance.


Categorization:


There are four different categories CPU governors can exist as.

1) Ondemand Based:
Works on "ramp-up on high load" principle. CPU busy-time is taken into consideration for scaling decisions. Members: Ondemand, OndemandX, Intellidemand, Lazy, Lagfree, PegasusQ, HYPER, Wheatley, Hotplug, HotplugX, AbyssPlug, AbyssPlugv2, Nightmare, Sleepy.


2) Conservative Based:
Works by biasing the phone to prefer the lowest possible clockspeed as often as possible. Members: Conservative, Lionheart, LionheartX

3) Interactive Based:
Works on "make scaling decision when CPU comes out of idle-loop" principle. Members: Interactive, InteractiveX, Intelliactive, Lulzactive, Luzactiveq, Smartass, SmartassV2, SmartassH3, Brazilianwax, SavagedZen, Dyninteractive, Interactive Pro


4) Unique Category:
These do not fall into any other category above and/or possess unique attributes. Members: Userspace, Powersave, Performance, Min Max, ZZmove, MSM DCVS, IntelliMM


5) Hybrid Category:
These have a mix of two (or more) CPU governor behaviors. Members: Smartmax, Dancedance, Performance May Cry(PMC), Ktoonservative, KtoonservativeQ


Here are some CPU Governors I recommend...



For performance:

- Interactive/InteractiveX
- Intelliactive
- Performance
- ElementalX
- HYPER
- Lionheart/LionheartX


For battery life:

- Ondemand
- Conservative
- Perfomance may cry (PMC)
- Powersave
- Smartmax

- Intellimm
- Bluactive
- Alucard


For balanced battery life and performance:

- Interactive/InteractiveX
- Intelliactive
- Ondemand/Ondemand

- ElementalX 
- Yankactive/YanksusQ
- Bluactive
- PegasusQ
- HYPER
- Impulse
- ZZMoove/ZZmanX


For gaming:

- Interactive/InteractiveX
- Intelliactive
- Performance

- Lionheart/LionheartX
- PegasusQ 
- ElementalX 
- Ondemand/OndemandX
- HYPER




What if my kernel allows my phone to run multiple governors?
Depending on how you would want to configure your phone's CPU, usually having the same governor for all CPUs is the way to go. This is because this will minimize any issues from occurring when the kernel is switching between governors and also this allows the phone to behave as it should stated in the CPU governor descriptions. If you want to have multiple CPU governor arrangements, here are some examples of arrangements that can be set:

Note: The following guide assumes your phone has 4 cpu cores. Not all phones and kernels support the feature to change individual governors!

Stock configuration
All CPUs running with ondemand/interactive/conservative based governor

Performance based, with slight battery saving features
CPU0+CPU1 performance based governor, CPU2+CPU3 ondemand based OR CPU0+CPU1+CPU2 performance based, CPU3 ondemand/conservative based

Ondemand with extra performance and with battery saving features (Recommended for extra performance) 
CPU0 performance based governor, CPU1+CPU2+CPU3 ondemand based

Pure performance 
All CPUs running performance based governor

Conservative+Ondemand based 
CPU0+CPU1 conservative based, CPU2+CPU3 ondemand based (or vise versa, doesn't really matter)

Note: It is not recommended to use performance based governors on the last couple of CPU cores as you will find higher battery drainage!


Benchmark graphs:



Setup:
Phone: Samsung Galaxy S2 i9100
Governor: as per indicated
Hotplug: Default
I/O Scheduler: SIO
Kernel: DorimanX 10.44 v008 
Frequency scaling: 200-1200mhz
App: Nofrills CPU
Test procedure: Opening stock browser, navigating home screens, navigating settings screen


CPU governor frequency times graph

Link to raw data: https://drive.google.com/file/d/0B3ApZsjOd2bzWDRnQjRsUTlLSlE/view?usp=sharing

Here are more graphs (thanks to Haldi!)


(Click to zoom in)
CPU governor CPU frequency usage graph



CPU governor power usage table