Develop Bugs

CPU governor and I/O Scheduler questions!

HI everyone. i have yet another question! lol.
i tried looking on google but noting specific for the epic. i was curious what the best cpu governor and the i/o scheduler is.
for the schedulers i have noop, cfq, bfq, deadline and sio
for cpu governors i have interactive, interactive x, ondemand, smartass, smartass v2 userspace, performance, conservative and powersave.

I use SmartassV2 and noop. SmartassV2, in my opinion, keeps the CPU frequencies low unless the power is really needed. Ondemand works well, but it is a little to generous some times. I use noop because it works well with flash memory. I am going to try out deadline because it seems like it would allow apps to load faster.

Just a quick FYI...
The SIO scheduler is supposed to be based on noop and deadline.
I haven't done much testing with it, but it specifically says it's designed for flash devices.
=]

nubecoder said:
Just a quick FYI...
The SIO scheduler is supposed to be based on noop and deadline.
I haven't done much testing with it, but it specifically says it's designed for flash devices.
=]
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I was doing some testing with Quadrant and SIO gets the highest score. I am going to try it out this week and see how it is in the long run. Thanks for the heads up nube.

Gavisann said:
I was doing some testing with Quadrant and SIO gets the highest score. I am going to try it out this week and see how it is in the long run. Thanks for the heads up nube.
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thank you. i noticed that sio was getting the best quadrant scores too.

nubecoder said:
Just a quick FYI...
The SIO scheduler is supposed to be based on noop and deadline.
I haven't done much testing with it, but it specifically says it's designed for flash devices.
=]
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Thank you for the amazing rom! one of the best for the epic right now.

kirt231 said:
Thank you for the amazing rom! one of the best for the epic right now.
Click to expand...
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=]
I don't do roms...
Some roms might be using my kernel though, so I understand the confusion.
=]

SIO seems faster but drains the heck out of my battery??
Im using VC deadline and ondemand and Im still at 100% 3 hrs unplugged with some minor messing around....ran the stopwatch for a bit trying to figure out what the hell was buzzing every (as it turns out) 1min. and have been messing around with the ui.
Nothing maujor but a few weeks ago I would have been at 90% by now easy

using smartassv2
with deadline quadrant score 2739
with sio 2733
both are good but as sio is lite version of deadline with a mix of noop so its balanced
deadline can cause some troubles if a program got stuck but its a performer
im using samsung galaxy sl i9003(ti omap3630 at 1.1ghz)

So far I am really loving SIO and smartassV2. My phone is fast when I need it to be and great on battery. From my rough calculations, I drain about 4% an hour when the phone is idle and about 7-10% an hour when I am browsing or watching a video. By the end of an average day, my battery lasts about 14-18 hours.

Help Please. What are the best Governers and I/O Schedulers....

I need not only performance, but battery life as well..
i currently have my clock at 998 high and 245 low
Performance governor and cfq i/o scheduler
but i want something that wont give me ANY lag, and give me good battery life

Depends on the kernel you use but currently I'm using MikG rom with the Underworld kernel, Smartassv2 governor, and SIO i/o scheduler. That's the best set up for ME. Just change things around and see what works out best for you and the set up you have. InteractiveX and Ondemand are also good Governors and Noop and deadline are good i/o schedulers as well.

The Performance governor that you are using now will drain the battery very fast because it will keep the cpu at the 998 most of the time or whatever you Change your max to

This should help a bit.
http://forum.xda-developers.com/showthread.php?p=26329039
The Creator of Suds N' Bubbles

Which Governor and I/O Scheduler you use?

What you think gives U best battery or performance? I am in cake kernel v.09 so in mine I have noticed I/O scheduler becomes deadline even if I select sio normally.
Which governor U like the most? smartassV2, interactiveX or performance? (I dont know why I am getting biased to Performance Day by day).
And whats the highest and lowest frequency U use? (I use 600-820MHz:silly

[REF][Super Friendly] Explanation of Governors, I/O Schedulers and Kernels [24-Nov]

Introduction
"It takes few hours to make a thread but it doesn't even take few seconds to say Thanks"- arpith.fbi
Click to expand...
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Code:
Don't be afraid to ask me anything.
I won't bite, but I might lick you.
Just thank me for this super brief thread.
Give credits to this thread by linking it if you're using any of my info.
Thank you to you too
Have you unlocked your bootloader of your current device ? If so, read it ! If not, learn the benifits ! :victory:
What is this thread about ? It is a very brief explanation of every governors and schedulers to let you find the best combo for your device.
I've been searching a lot about informations about Kernels, Governors, I/O Schedulers and also Android Optimization Tips. No matter its Google or XDA or other android forums. I will go into it and try the best I can to find these infos. So I thought of sharing it to here for the Xperia S, Acro S, and Ion[COLOR] users.
My main reason to share this is to benefit users for better knowledge about Kernels, Governors, I/O Schedulers and Tips on Android Optimization. I'm not aware of whether where this should be posted, its related to kernels, governors and schedulers so I think it would be best if I share it to here. Yes, I wrote it word by word with references.Happy learning. :angel:
After months on XDA, no matter its in a development forum or Off Topic forum. Users kept on asking what's this what's that. And I'm sure that not all members will understand what is it until they bump into my thread
FAQs regarding on :-
-I/O Schedulers
-Kernel Governers
-Better RAM
-Better Battery
-FAQs
*Will add more when I found something useful.
Click to expand...
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I do a lot of asking by PM, to learn, it doesn't matter whether its a stupid one. (People who know me understands)
With my experience and lots of asking. I managed to find a lot of infos that we can use to optimize our phone.
I will try to explain as clear as I can.
Governors :-
-Smoothass
-Smartass
-SmartassV2
-SavagedZen
-Interactivex
-Lagfree
-Minmax
-Ondemand
-Conservative
-Brazilianwax
-Userspace
-Powersave
-Performance
-Scary
-Lulzactive *
-Intellidemand *
-Badass *
-Lionheart *
-Lionheartx *
-Virtuous *
* Not enough information about it, will add it later on.
Explanation
OnDemand
Brief
Available in most kernels, and the default governor in most kernels. When the CPU load reaches a certain point, OnDemand will rapidly scale the CPU up to meet the demand, then gradually scale the CPU down when it isn't needed.
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Review
Brief says all. By a simple explantion, OnDemand scales up to the required frequency to undergo the action you are doing and rapidly scales down after use.
Conservative
Brief
It is similar to the OnDemand governor, but will scale the CPU up more gradually to better fit demand. Conservative governor provides a less responsive experience than OnDemand, but it does save batter
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Review
Conservative is the opposite of Interactive; it will slowly ramp up the frequency, then quickly drops the frequency once the CPU is no longer under a certain usage.
Interactive
Brief
Available in latest kernels, it is the default scaling option in some stock kernels. Interactive governor is similar to the OnDemand governor with an even greater focus on responsiveness.
Click to expand...
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Review
Interactive is the opposite of Conservative; it quickly scales up to the maximum allowed frequency, then slowly drops the frequency once no longer in use.
Performance
Brief
Performance governer locks the phone's CPU at maximum frequency. While this may sound like an ugly idea, there is growing evidence to suggest that running a phone at its maximum frequency at all times will allow a faster race-to-idle. Race-to-idle is the process by which a phone completes a given task. After that it returns the CPU to extremely efficient low-power state.
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Review
Good at gaming, Really good. Disadvantages are it may damage your phone if too much usage.
Powersave
Brief
The opposite of the Performance governor, the Powersave governor locks the CPU frequency at the lowest frequency set by the user.
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Review
Set it to your desired minimum frequency and you won't have to look for your charger for once in a while.
Scary
Brief
A new governor wrote based on Conservative with some Smartass features, it scales accordingly to Conservative's way. It will start from the bottom. It spends most of its time at lower frequencies. The goal of this is to get the best battery life with decent performance. It will give the same performance as Conservative right now.
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Review
Hmm.. Overall I don't see any difference. After I understand its main objective. I was very curious and decided to use it again. Results are the same.. No difference. Report to me if anyone has tested this.
Userspace
Brief
Userspace is not a governor pre-set, but instead allows for non-kernel daemons or apps with root permissions to control the frequency. Commonly seen as a redundant and not useful since SetCPU and NoFrills exist.
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Review
Highly not recommended for use.
Smartass
Brief
It is based on the concept of the Interactive governor.
Smartass is a complete rewrite of the code of 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.
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Review
Smartass is rather the governer that will save your battery and make use of your processor for daily use. Like the brief explantion said " Smartass will spend much more time on lower frequencies." So logically you don't need for sleep profiles anymore.
SmartassV2
Brief
Theoretically a merge of the best properties of Interactive and OnDemand; automatically reduces the maximum CPU frequency when phone is idle or asleep, and attempts to balance performance with efficiency by focusing on an "ideal" frequency.
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Review
This is a much favourite to everybody. I believe almost everyone here is using SmartassV2. Yes, it is better than Smartass because of its speed no scaling frequencies from min to max at a short period of time.
Smoothass
Brief
A much more aggressive version of Smartass that is very quick to ramp up and down, and keeps the idle/asleep maximum frequency even lower.
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Review
In my personal experience, this is really useful for daily use. And yes, I'm using it all the time. It may decrease your battery life. I saw it OC itself to 1.4 gHz when I set it to 1.2. Good use. Recommended.
Brazilianwax
Brief
Similar to SmartassV2. More aggressive scaling, so more performance, but less battery.
Click to expand...
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Review
Based on SmartassV2. But its advantage is a much more performance wise governor.
SavagedZen
Brief
Another SmartassV2 based governor. Achieves good balance between performance & battery as compared to Brazilianwax.
Click to expand...
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Review
Not much difference compared to SmartassV2. But it is a optimized version of it.
Lagfree
Brief
Again, similar to Smartass but based on Conservative rather than Interactive, instantly jumps to a certain CPU frequency after the device wakes, then operates similar to Conservative. However, it has been noted as being very slow when down-scaling, taking up to a second to switch frequencies.
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Review
Used it before. Like the name of the governor, I didn't experience any lag whatsoever. Another governor based on performance, but not battery efficient.
MinMax
Brief
MinMax is just a normal governor. No scaling intermediate frequency scaling is used.
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Review
Well.. it's too normal that I can't really say anything about it..
Interactivex
Brief
InteractiveX governor is based heavily on the Interactive governor, enhanced with tuned timer parameters to optimize the balance of battery vs performance. 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.
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Review
A better understanding from the brief to you users, this is an Interactive governor with a wake profile. More battery friendly than Interactive.
Due to current kernels doesn't have these governors. I will be delaying the explanation, its very interesting. If you want it ASAP, post below
-Lulzactive *
-Intellidemand *
-Badass *
-Lionheart *
-Lionheartx *
-Virtuous *
**********************************************************************************************************************************************************************
I/O Schedulers(thanks to droidphile)
Deadline
Goal is to minimize I/O latency or starvation of a request. The same is achieved by round robin policy to be fair among multiple I/O requests. Five queues are aggressively used to reorder incoming requests.
Advantages:
Nearly a real time scheduler.
Excels in reducing latency of any given single I/O.
Best scheduler for database access and queries.
Bandwidth requirement of a process - what percentage of CPU it needs, is easily calculated.
Like noop, a good scheduler for solid state/flash drives.
Disadvantages:
When system is overloaded, set of processes that may miss deadline is largely unpredictable.
Click to expand...
Click to collapse
Noop
Inserts all the incoming I/O requests to a First In First Out queue and implements request merging. Best used with storage devices that does not depend on mechanical movement to access data. Advantage here is that flash drives does not require reordering of multiple I/O requests unlike in normal hard drives.
Advantages:
Serves I/O requests with least number of cpu cycles. (Battery friendly?)
Best for flash drives since there is no seeking penalty.
Good throughput on db systems.
Disadvantages:
Reduction in number of cpu cycles used is proportional to drop in performance.
Click to expand...
Click to collapse
Anticipatory
Based on two facts
i) Disk seeks are really slow.
ii) Write operations can happen whenever, but there is always some process waiting for read operation.
So anticipatory prioritize read operations over write. It anticipates synchronous read operations.
Advantages:
Read requests from processes are never starved.
As good as noop for read-performance on flash drives.
Disadvantages:
'Guess works' might not be always reliable.
Reduced write-performance on high performance disks.
Click to expand...
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BFQ
nstead of time slices allocation by CFQ, BFQ assigns budgets. Disk is granted to an active process until it's budget (number of sectors) expires. BFQ assigns high budgets to non-read tasks. Budget assigned to a process varies over time as a function of it's behavior.
Advantages:
Believed to be very good for usb data transfer rate.
Believed to be the best scheduler for HD video recording and video streaming. (because of less jitter as compared to CFQ and others)
Considered an accurate i/o scheduler.
Achieves about 30% more throughput than CFQ on most workloads.
Disadvantages:
Not the best scheduler for benchmarking.
Higher budget assigned to a process can affect interactivity and increased latency.
Click to expand...
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CFQ
Completely Fair Queuing scheduler maintains a scalable per-process I/O queue and attempts to distribute the available I/O bandwidth equally among all I/O requests. Each per-process queue contains synchronous requests from processes. Time slice allocated for each queue depends on the priority of the 'parent' process. V2 of CFQ has some fixes which solves process' i/o starvation and some small backward seeks in the hope of improving responsiveness.
Advantages:
Considered to deliver a balanced i/o performance.
Easiest to tune.
Excels on multiprocessor systems.
Best database system performance after deadline.
Disadvantages:
Some users report media scanning takes longest to complete using CFQ. This could be because of the property that since the bandwidth is equally distributed to all i/o operations during boot-up, media scanning is not given any special priority.
Jitter (worst-case-delay) exhibited can sometimes be high, because of the number of tasks competing for the disk.
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SIO
Simple I/O scheduler aims to keep minimum overhead to achieve low latency to serve I/O requests. No priority quesues concepts, but only basic merging. Sio is a mix between noop & deadline. No reordering or sorting of requests.
Advantages:
Simple, so reliable.
Minimized starvation of requests.
Disadvantages:
Slow random-read speeds on flash drives, compared to other schedulers.
Sequential-read speeds on flash drives also not so good.
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VR
Unlike other schedulers, synchronous and asynchronous requests are not treated separately, instead a deadline is imposed for fairness. The next request to be served is based on it's distance from last request.
Advantages:
May be best for benchmarking because at the peak of it's 'form' VR performs best.
Disadvantages:
Performance fluctuation results in below-average performance at times.
Least reliable/most unstable.
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Credits
-droidphile
-kokzhanjia

Reserved for kernel info

Many thanks for sharing your knowledge on all of this! You made it very easy to understand
Sent from my LT26i using xda app-developers app

Thank u very much!

Thanks a lot !
Sent from my Xperia S using xda premium

Thanks for gathering all this info, it is a very handy guide.
You may want to add that this all works on locked bootloader as well. The big difference is you only get the stock kernel choices & no over clock. I use conservative & cfq thru 'cpu master' my locked ION
~Jaramie
Sent from my ION

how about hotplug - pegasusq ??????? can u explain this governors ?????

Segarys said:
Many thanks for sharing your knowledge on all of this! You made it very easy to understand
Sent from my LT26i using xda app-developers app
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davidbar93 said:
Thank u very much!
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Xecutioner_Venom said:
Thanks a lot !
Sent from my Xperia S using xda premium
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ToledoJab said:
Thanks for gathering all this info, it is a very handy guide.
You may want to add that this all works on locked bootloader as well. The big difference is you only get the stock kernel choices & no over clock. I use conservative & cfq thru 'cpu master' my locked ION
~Jaramie
Sent from my ION
Click to expand...
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Thanks
saberamani said:
how about hotplug - pegasusq ??????? can u explain this governors ?????
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Yeah, i will add it along with other unexplained governors
Thanks for reminding..

[Xperia S]could some1 tell me more about what to choose for I/O scheduler??

Curretly using trinity ultimate kernel with the TrinityVengeanceRaptorX rom
Got noop, deadline, cfq, sio, zen, vr
which one give more performance and which save battery??
or which of them shall I choose on different purpose? (for example gaming)
sorry i'm a noob
thankyou

tl;dr: Deadline is best.

Felimenta97 said:
tl;dr: Deadline is best.
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does it push performance?
or what are the difference??

KWOKSFUNG said:
does it push performance?
or what are the difference??
Click to expand...
Click to collapse
Read this thread. You will get some idea about I/O scheduler.
After reading you can set it by yourself depending on what you need.
In the thread advantages and disadvantages of each I/O schedulers are described.