I'm on the latest CM7 build and would like to know the pros and cons of using each kernel. Hopefully someone can enlighten me.
I'm on Pershoot's right now, btw.
personally i like the pershoot kernels, they give u more frequencies to choose from... now this isnt really a big deal when u picking the overclock frequency (844Mhz vs 864Mhz vs 883Mhz isnt a big difference really), but given that the kernel can vary the frequencies in real-time means that the kernel has more options to chose from, also given a good algorithm that picks the frequencies it should result in better performance and less battery use (theoretically since the power required for 806MHz is less than 883Mhz).
Also pershoot kernels are UV, which should mean that the CPU is using less power to run at any given frequency (compared to running at that exact frequency with a non UV kernel).
Having said so, CM kernel gives u more options regarding the governors, under the original CM kernel i always picked the Conservative governor which gave me amazing battery life... this option is not available under the pershoot kernel and i believe pershoot recommends using the OnDemand option (not a 100% on this one though).
so in my opinion, and if am correct it's mostly a preference thing. I use the pershoot kernels.
let me know if am missing anything
awsrasool said:
personally i like the pershoot kernels, they give u more frequencies to choose from... now this isnt really a big deal when u picking the overclock frequency (844Mhz vs 864Mhz vs 883Mhz isnt a big difference really), but given that the kernel can vary the frequencies in real-time means that the kernel has more options to chose from, also given a good algorithm that picks the frequencies it should result in better performance and less battery use (theoretically since the power required for 806MHz is less than 883Mhz).
Also pershoot kernels are UV, which should mean that the CPU is using less power to run at any given frequency (compared to running at that exact frequency with a non UV kernel).
Having said so, CM kernel gives u more options regarding the governors, under the original CM kernel i always picked the Conservative governor which gave me amazing battery life... this option is not available under the pershoot kernel and i believe pershoot recommends using the OnDemand option (not a 100% on this one though).
so in my opinion, and if am correct it's mostly a preference thing. I use the pershoot kernels.
let me know if am missing anything
Click to expand...
Click to collapse
Thank you so much! Just the answer I was looking for! Very informative and straight-forward, thanks.
Looks like I'll be sticking to Pershoot's.
awsrasool said:
Having said so, CM kernel gives u more options regarding the governors, under the original CM kernel i always picked the Conservative governor which gave me amazing battery life... this option is not available under the pershoot kernel and i believe pershoot recommends using the OnDemand option (not a 100% on this one though).
Click to expand...
Click to collapse
You're correct. Pershoot uses the ondemand governor because he says it's more stable at the higher cpu clock cycles. Few issues with FC's, lockups, and reboots. Though I do love the interactive governor (still want the smartass gov) he is correct from what I've personally experienced. That may be due to small variances in the kernels though despite coming from the same source but who knows.
Pershoot also has a .zip for every kernel that's full of some /lib files to add extra functions to your device, most users probably won't find a use for them though.
KCRic said:
Pershoot also has a .zip for every kernel that's full of some /lib files to add extra functions to your device, most users probably won't find a use for them though.
Click to expand...
Click to collapse
Can you please explain these extra functions and how to apply them please?
Wouldn't mind having some new functions
Sent from my HTC Vision using XDA App
I've found I get better battery life with Pershoot's kernel compared to the stock CM kernel using the same clocks speeds and governor (245 Mhz-1017 Mhz, Ondemand). No statistics to throw up though.
been looking through a lot of kernels and Roms, anyone have any particular ones they prefer and why? bit of help on mix and match.
thanks
Stock, or stock voltage and overclocked.
The kernel handles voltages better than manual users do. The rest of the stuff is mostly fluff.
I'm running codename rom at the moment, overclocked to 1.3 ondemand, changed nothing else, didn't go near voltage settings, but mostly just run it stock
adrynalyne said:
Stock, or stock voltage and overclocked.
The kernel handles voltages better than manual users do. The rest of the stuff is mostly fluff.
Click to expand...
Click to collapse
So undervolting and hotplug aren't really beneficial for improving battery life?
I was running morfic's trinity kernel. you can find the thread here
Goal of this little project is to dispel myths and hearsay and trying to assess the elusive performance of custom kernels for our beloved SGS I9000.
So far this has proven quite challenging as there is no single good benchmark on Android (yet):
a lot of people have been misled by ridiculous Quadrant scores: ridiculous because, with some small tweaks which do not affect real performance in any way, shape or form, it is possible to boost the Quadrant score by factor 3x.
You're free to believe that your SGS I9000 which scores 3000+ on Quadrant is faster than a SGS II, but then please leave this thread and move on.
some kernels may seem smooth with some games, and get high scores on some synthetic benchmark, yet the UI appears "laggy" and stutters a lot in comparison to other kernels which score lower on the same benchmark
some popular benchmarks give results with unacceptably low reproducibility, i.e. if you run them multiple times without changing a thing on your system, you get scores varying by 50% of more, in a completely random fashion
most popular benchmarks do not measure or take into account multitasking and CPU contention with other applications, yet on a typical usage one has background tasks such as the media scanner or synchronization which kick in often and unpredictably
So this will be mostly a work in progress, i'm testing several benchmarks and several kernels in multiple combinations, trying to analyze which benchmarks offer certain criteria which make them useful, namely:
Reproducibility of results: running the same tests multiple times, should result in a very small variance of the final score
Performance separation: benchmarks which are too "synthetic" and show only a dependency on clock speed are not useful to discriminate "fast" kernels from "slow" kernels
Performance representation: we all know when a kernel "looks" or "feels" fast or smooth. If a benchmarks shows you that a "laggy" kernel scores higher than a fast and responsive one, it's likely that the benchmark is not well designed
I'll work more on this thread explaining my (current) choice of tests and what they're good for.
But for now i'll just post a link to the summary table, and give a brief recommendation concerning popular ICS kernels; recommendation which i'll explain in the coming days.
Base ROM:
Slim ICS 2.8
(because is fast, smooth and has the least background stuff of all ICS ROMs which i tested)
Test Conditions:
Whenever possible, i tried to overclock the kernels to 1.2GHz which most / all phones should have no trouble achieving.
In case of Semaphore i had to use the bus / live overclock but it wasn't fully stable at 1.2GHz on my phone so i ran most of the tests at 1.14GHz.
Tested Kernels:
Stock Teamhacksung V17
Devil 1.1.6b BFS
Devil 1.1.6b CFS
Icy Glitch V14 b
Semaphore ICS 0.9.5b
Recommendation:
Devil 1.1.6b CFS, Icy Glitch V14b (with SmartassV2 and FIOPS), and Midnight ICS (with a tweaked Conservative) are trading blows for the fastest kernel.
At the time of testing, Midnight is slightly worse in terms of overclocking though, apparently due to different voltages, also it doesn't allow overclocking beyond 1.2GHz.
But what's interesting is that it achieves great performance while using a tweaked conservative governor.
Devil 1.1.6b BFS is good but obviously inferior to its CFS brother.
Semaphore has the lowest cache and memory latency in the multithreaded test, it also has impressive sd card read speed and in general appears super responsive, but it's a bit worse in 3D gaming and especially it lacks "true" overclocking, "live overclocking" changes the bus clock and is way more unstable, in fact on my phone i couldn't run it stable at 1.2GHz.
All kernels are significantly faster than the stock teamhacksung's kernel, so you have no excuses not to upgrade to one of the popular custom kernels!
ICS 4.0.4
Started testing Android ICS 4.0.4 kernels on Slim ICS 3.2.
All tested kernels are "huge mem" versions with 380+MB of available RAM, without breaking video playback or 720p recording.
Summary:
the stock kernel from Teamhacksung is now a very respectable performer, unless you plan to overclock probably you don't need to install one of the other kernels
Semaphore, Midnight and Devil are all very fast and smooth
Results table:
https://docs.google.com/spreadsheet/ccc?key=0AuBUEB4dGFSSdHIyN2VIeWU4QnhLOFpJejFPWDh5S1E
Res 1
One request for the kernel developers:
could you please post me what are your preferred / recommended settings in terms of Governor and I/O Scheduler?
Only one configuration per kernel please, as running these tests is rather time consuming.
Test Settings
So for anybody who wants to follow the same methodology as I used to test kernels, please pay attention that in some tests i didn't use stock settings, to try to improve the reproducibility of the results.
Before all test, i put the phone in flight mode, and disable all synch services.
Antutu: DB I/O and SD Write and Read have poor reproducibility. So i run these tests separately 5 times, and take the best scores.
RealPi: the number of iterations is increased by factor 10x i.e.: 100000 digits
MPAC: lots of customization here. Also be careful as it's not very stable and some settings will make it crash.
All tests: 8 threads (or 8 producer / consumer pairs)
CPU: 10000000 iterations, use case: integer (i'm considering to add logical too)
Memory: stock apart for nr of threads. Repeat the test 5 times and get best numbers
Cache: 40 iterations
Res 3
With this should be enough.
Judging from those results, CFS Devil looks really promising.
Semaphore live oc stability issues happen only on Slim ICS indeed. On ICSSGS I have perfect stability at 1.2 ghz. And performance is just great, paired with very good battery life.
GT-i9000 / ICSSGS 4.2 / Semaphore 0.9.0
A quick question: did you lock the max freq to eliminate the "governor" variable?
Because each kernel could have governor's tweaks that the other don't.
Based on what you posted here, the differences between Glitch and Devil is practically none.
I tested both and didn't feel any tangible difference, in the end, it comes down to the unique features of each kernel.
Overclocking bus vs adding an extra step aren't even slightly comparable. Maybe do tests not overclocked?
Also there is a new glitch build with 100% working bln.
Sent from my GT-I9000 using xda premium
+1 for tests without overclock. Majority of us, users do not overclock. Maybe a seperate test for overclocking could be nice , but comparisons should be done with stock speeds imho.
Thanks for the time and effort. We needed this.
Overclocking bus Vs adding an extra step isn't an apple to apple comparison, I agree.
However my goal was to use each kernel in the best possible way, and if some kernels have the possibility to use higher multipliers / extra frequency steps, that is an advantage for the user, compared to the kernels who only offer live overclock.
Don't get me wrong, i love Semaphore and i've been using it for a long time.
And i have no doubt that some users can get it stable with live overclock to 1.2GHz.
But that is the ceiling, while with other kernels even my phone can reach stable overclocks of 1.5GHz, and that is something to consider.
I chose as the basis for my tests an overclock of 1.2GHz because it's something which practically everybody can use, without massive battery drain, overheat or shortening the life of the device.
I'll try to add measurements at stock speeds for those who don't like to overclock.
cba1986 said:
A quick question: did you lock the max freq to eliminate the "governor" variable?
Because each kernel could have governor's tweaks that the other don't.
Click to expand...
Click to collapse
I didn't want to take the governor variable out.
Because, as you said, each kernel could use (and often does) governor tweaks which make the kernel "special" or different from the others, and that has to be taken into account in evaluating them.
Because nobody will use the phone locked at the maximum frequency.
So for me the governor and its tweaks is part of the user experience of a certain kernel, and a distinctive factor.
At the end, all kernels are coming from almost the same sources, so it's the little things which make the difference.
phzi said:
Also there is a new glitch build with 100% working bln.
Sent from my GT-I9000 using xda premium
Click to expand...
Click to collapse
That's great!
This test i run is not the "be all end all", it was just a recommendation at the time of writing.
Pipperox said:
Overclocking bus Vs adding an extra step isn't an apple to apple comparison, I agree.
However my goal was to use each kernel in the best possible way, and if some kernels have the possibility to use higher multipliers / extra frequency steps, that is an advantage for the user, compared to the kernels who only offer live overclock.
Click to expand...
Click to collapse
Agreed but, then again, benchmarks should be done at original CPU clock IMHO.
Otherwise, results are distorted.
HiKsFiles said:
Agreed but, then again, benchmarks should be done at original CPU clock IMHO.
Otherwise, results are distorted.
Click to expand...
Click to collapse
agreed. Especially since stock team hacksung seems to be clocked at 1GHz
what's the point of the comparison? Really?
As expected, there is no noticeable difference between all 1.2 GHz kernels.
It's not as if there was a real difference between them anyway.
zorxd said:
agreed. Especially since stock team hacksung seems to be clocked at 1GHz
what's the point of the comparison? Really?
As expected, there is no noticeable difference between all 1.2 GHz kernels.
It's not as if there was a real difference between them anyway.
Click to expand...
Click to collapse
That's not quite true.
If you look closer, you'll see that Devil CFS has quite a distinct advantage over all others in 3D tests.
The point of the comparison between stock hacksung @1.0GHz and the others, who can overclock, is to show what kind of benefit you get from switching to kernels which are overclock friendly.
Especially considering that you can't assume that a 20% clock speed increase will bring a 20% performance speedup across the board.
At last, i'd say that you may have "expected" that the kernels tested at 1.2 GHz don't have such a difference in performance.
But expectations have to be verified.
I tried to answer the questions:
On Devil's kernel, is BFS really better than CFS?
The "popular belief" is that BFS is faster than CFS.
According to my tests, CFS results faster instead.
Another question may be, what kernel gives you the best gaming performance.
If you pay attention to the An3D Bench XL, you'll see that Semaphore 0.9.5b, even overclocked a 1.2GHz, is significantly slower than Devil.
If i recall correctly Semaphore Author claimed that some kernel developers overclock GPU, and he didn't. Idk anything about it, but i recall something about it.
Is it possible to overclock only GPU, without overclocking CPU??
zipgenius said:
so you should benchmark them without setting anything. Average users don't overclock and don't change governor or scheduler: they flash the new kernel and stop.
Click to expand...
Click to collapse
I completely agree on benchmarking every kernel at the same frequency (stock 1Ghz max) but I think there are two different options for further benchmarking:
1) Benchmark kernels configured as similar as possible regarding CPU governor, IO scheduler, readahead -> comparable results for all kernels.
2) Benchmark kernels with default settings (only makes sense if all compared kernels are optimized for similar purpose like performance, does not make sense if a kernel does *not* focus on max. performance and uses e.g. Conservative CPU governor as default setting.
@Pipperox: Would it be possible to check my Mindnight-ICS dev version with your benchmark suite? I'd be really interested in the results as you use the same setup for all kernels (1.2Ghz would not be a problem, does not use LiveOC but old school 1/1.128/1.2Ghz OC).
Interesting thread... I never used devil's CFS version, always BFS. Will try CFS out now.
@Mialwe Where can we get your ics kernel?
mialwe said:
I completely agree on benchmarking every kernel at the same frequency (stock 1Ghz max) but I think there are two different options for further benchmarking:
1) Benchmark kernels configured as similar as possible regarding CPU governor, IO scheduler, readahead -> comparable results for all kernels.
2) Benchmark kernels with default settings (only makes sense if all compared kernels are optimized for similar purpose like performance, does not make sense if a kernel does *not* focus on max. performance and uses e.g. Conservative CPU governor as default setting.
@Pipperox: Would it be possible to check my Mindnight-ICS dev version with your benchmark suite? I'd be really interested in the results as you use the same setup for all kernels (1.2Ghz would not be a problem, does not use LiveOC but old school 1/1.128/1.2Ghz OC).
Click to expand...
Click to collapse
Sorry guys, i understand your logic but i do not fully agree with it.
I'm not comparing overclocked kernels with heavy tweaking of voltages and special settings with which they only work.
I did the "poor man"'s overclock, setting to 1.2GHz using NSTools, a setting where 95% of phones should have no problem working.
I think that if some kernels offer you this possibility while others do not, it is fair to use this "advantage" that they have over the other kernels.
Because a lot of users will have the possibility to do the same as i do, without esoteric knowledge and with just a couple of clicks in the menus.
That being said, "due to popular demand" i will also try to retest those kernels at 1.0GHz as soon as i get a bit of time.
BUT in my recommendations, i will also consider the overclocking capabilities.
@mialwe: sure, i'll give a run to your kernel as well!
mialwe said:
@Pipperox: Would it be possible to check my Mindnight-ICS dev version with your benchmark suite? I'd be really interested in the results as you use the same setup for all kernels (1.2Ghz would not be a problem, does not use LiveOC but old school 1/1.128/1.2Ghz OC).
Click to expand...
Click to collapse
Dude, sorry but i don't seem to find your ICS kernel anywhere.. can you provide a link?
i love the popcorn kernel because it uses my fav governor "Aggressive".
its so speedy and responsive. why don't the devs more kernels like this?
what kernels you guys prefer? any specific reason?
Thanks
Franco Kernel because it's the best.
Sent from my Galaxy Nexus using xda premium
Hotplug kernel, when screen is off it close one of two core
Governors are pretty funny, really. Every Tom, ****, and Harry modifies an existing governor a bit and them calls it their own, giving it a new name.
Really if you stick the main governors, it works just as well. So much of what you see as performance differences is like everything else; placebo. That would be why not everyone uses 'insert Governor'.
I have mixed feelings about Hotplug, but that is for another time.
I recently rooted and installed a custom Rom and ElementalEx Kernel. I noticed that the default profiler for the Pixel XL is something called sched which appears to be a fairly conservative governor. I changed it to interactive which I normally use on other phones and battery life suffered considerably. I switched it back to sched and cpu frequencies are much lower but I don't notice any drop in performance. I tried researching sched but haven't found much. Anyone know how this governor works?
Sched is the most efficient governor for our pixel.
The real question is why do you want to change the governor? If you really want some things to mess with to increase battery and/or performance then check out "L speed (boost&battery)" in the play store. And No, this isn't shameless advertising either, the dev is right here in our forums.
noidea24 said:
Sched is the most efficient governor for our pixel.
The real question is why do you want to change the governor? If you really want some things to mess with to increase battery and/or performance then check out "L speed (boost&battery)" in the play store. And No, this isn't shameless advertising either, the dev is right here in our forums.
Click to expand...
Click to collapse
It was a reflex reaction because I'm used to using Interactive and the CPU frequencies seemed really low compared with what I would see on the 6P. Those frequencies on the 6P would result in a noticable performance lag. But I guess the phone design is really different so you can't compare them that way. I'll check out L Speed. Never heard of it. Thanks.
jhs39 said:
It was a reflex reaction because I'm used to using Interactive and the CPU frequencies seemed really low compared with what I would see on the 6P. Those frequencies on the 6P would result in a noticable performance lag. But I guess the phone design is really different so you can't compare them that way. I'll check out L Speed. Never heard of it. Thanks.
Click to expand...
Click to collapse
Same. Coming from the 6p / 5x scene. The best governor was interactive, especially due to all the tweaks and changes that could be applied to the governor (like on ElementalX).
But no, pixel is almost dedicated to sched. I honestly don't think anyone else is running anything else and getting decent results from it
Pixel/XL Uses EAS so governors like Sched, Schedutil etc etc. Meanwhile every other Android device uses HMP your regular governors like Interactive, Ondemand, performance, conservative etc
So it's recommended to use Sched as the defualt but you can learn more about EAS here Also Freak07 has some great info on EAS and it's govenors here
jhs39 said:
It was a reflex reaction because I'm used to using Interactive and the CPU frequencies seemed really low compared with what I would see on the 6P. Those frequencies on the 6P would result in a noticable performance lag. But I guess the phone design is really different so you can't compare them that way. I'll check out L Speed. Never heard of it. Thanks.
Click to expand...
Click to collapse
Same. Coming from the 6p / 5x scene. The best governor was interactive, especially due to all the tweaks and changes that could be applied to the governor (like on ElementalX).
But no, pixel is almost dedicated to sched. I honestly don't think anyone else is running anything else and getting decent results from it
noidea24 said:
Same. Coming from the 6p / 5x scene. The best governor was interactive, especially due to all the tweaks and changes that could be applied to the governor (like on ElementalX).
But no, pixel is almost dedicated to sched. I honestly don't think anyone else is running anything else and getting decent results from it
Click to expand...
Click to collapse
All kinds of us are running schedutil gov on custom kernels. It's the next iteration of EAS sched gov. Better performance than sched.
Yeah same here, I would always use L Speed or some different governor on previous phones than default, cause default was always not the most efficient, both performance and battery backup wise, but on Pixel there is no need. In fact devs have suggested us to use the default Sched governor, so I am sticking with it.
Anyone on ElementalEx change any settings other than the governor to improve performance on the Pixel XL? A lot of the available settings are different than I'm used to.
Hi, everyone I'm s7edge owner would like to use a the Google pixel governor, can someone show me the direction please? Thanks
lovetv said:
Hi, everyone I'm s7edge owner would like to use a the Google pixel governor, can someone show me the direction please? Thanks
Click to expand...
Click to collapse
Not possible without an EAS compatible ROM/Kernel
ithehappy said:
Yeah same here, I would always use L Speed or some different governor on previous phones than default, cause default was always not the most efficient, both performance and battery backup wise, but on Pixel there is no need. In fact devs have suggested us to use the default Sched governor, so I am sticking with it.
Click to expand...
Click to collapse
I think the devs suggest using the sched governor because they are either too lazy or not knowledgeable enough to create other governors that are compatible with the Pixel. The sched governor is far from efficient. It's clearly a performance based governor and it allows the Pixel battery and CPU to get very hot very quickly. The Pixel CPU can get to 130F just performing what most people would consider standard tasks on their phones. I'm not even talking about gaming or anything remotely CPU intensive. How long do you think these phones are actually going to last when they heat up so much?
What's the difference between sched and schedutil? I saw schedutil is default on the ElementalX for !y Pixel 2 XL.