Does anyone know if it will eventually be possible to overclock the GPU in the Nexus 5 to match the S800 MSM8974AB chip?
The S800 chip in the Nexus 5 is the MSM8974 chip which has the GPU clock of 450MHz, but there is another version of the S800 chip called the MSM8974AB which has the GPU clocked at 550MHz.
Here is a link for anyone that is interested in seeing all the differences between the MSM8974 and the MSM8974AB
http://www.androidbeat.com/2013/09/difference-snapdragon-800-2-2ghz-2-3ghz/
It will definitely be possible with kernels. Don't know how safe it will be to overclock by 100mhz, but on my HTC One Elemental X gives the option to overclock from stock 400mhz to 550 (very bad for the device though). So the Nexus 5 will definitely be able to hit 550 as well.
Adreno 330 overclock 450MHz to 550MHz
Hello,
Is there any update about this?
I Overclocked the CPU to 2.5GHz via a custom kernel, but I am unable to pass the 450MHz of the CPU.
Please let me know if you have a solution.
Thanks
which device use MSM8974AB chip?
I have the Z1 also, which has the same chipset as the N5. There is a custom kernel for the z1 that OCs the GPU to 533mhz which I run stably with excellent battery life. So I'm sure it's possible to do the same with the N5 since it's the same processor. I'm sure one of the smart devs here can look at the github posted here: http://forum.xda-developers.com/showthread.php?t=2448613
my GOD, what did i just read
http://www.qualcomm.com/media/blog/...gies-newest-snapdragon-805-ultra-hd-processor
Adreno 420? As a heavy gamers, this thing really make me annoying -_-
I have 600MHz GPU overclock implemented in my kernel for the Xperia Z1, which uses the lower binned version of the msm8974 (the one that comes with a stock clock-speed of 2.2GHz).
We have 450/487.5/533/600 MHz scaling steps.
You can take a look at the OC commits here, it's pretty straight-forward:
https://github.com/RevolutionDev/android_kernel_sony_msm8974/commit/4136fb7713887a0561d399ecc1adc3af55d65a88
https://github.com/OmniHonami/android_kernel_sony_msm8974/commit/96dd342f1015a71e9139de8057ee16b86c6005ff
Androguide.fr said:
I have 600MHz GPU overclock implemented in my kernel for the Xperia Z1, which uses the lower binned version of the msm8974 (the one that comes with a stock clock-speed of 2.2GHz).
We have 450/487.5/533/600 MHz scaling steps.
You can take a look at the OC commits here, it's pretty straight-forward:
https://github.com/RevolutionDev/android_kernel_sony_msm8974/commit/4136fb7713887a0561d399ecc1adc3af55d65a88
https://github.com/OmniHonami/android_kernel_sony_msm8974/commit/96dd342f1015a71e9139de8057ee16b86c6005ff
Click to expand...
Click to collapse
@Androguide.fr
Is it possible to control also gpu voltage?
You got 600mhz at stock voltage?
Carter07 said:
@Androguide.fr
Is it possible to control also gpu voltage?
You got 600mhz at stock voltage?
Click to expand...
Click to collapse
It is, but not yet implemented on the nexus 5 custom kernels.
Also mhz does not mean voltage (V) or (uVolts on this case). MHz means a frequency of 1 million times per second (used on this case for CPU, GPU, RAM speed)
GUGUITOMTG4 said:
It is, but not yet implemented on the nexus 5 custom kernels.
Also mhz does not mean voltage (V) or (uVolts on this case). MHz means a frequency of 1 million times per second (used on this case for CPU, GPU, RAM speed)
Click to expand...
Click to collapse
True, but @Carter07 is right that if the maximum allowed voltage is too low the GPU won't be able to sustain higher frequencies, as those demand more power.
The 600MHz OC is stable with the stock voltage, though, at least on the Z1 it is.
Androguide.fr said:
True, but @Carter07 is right that if the maximum allowed voltage is too low the GPU won't be able to sustain higher frequencies, as those demand more power.
The 600MHz OC is stable with the stock voltage, though, at least on the Z1 it is.
Click to expand...
Click to collapse
indeed, I misinterpreted him
You can flash Bricked kernel and use Kcontrol to force-overclock your gpu up to 650...but I wouldn't recommend anything above 550 since you will get little to no performance and it'll consume a lot more battery
Is there a huge performance boost noticable if you oc the cpu? And what's about the battery life?
lol98lol98 said:
Is there a huge performance boost noticable if you oc the cpu? And what's about the battery life?
Click to expand...
Click to collapse
There's no recognisable boost in performance apparently. And yes,battery drain will be higher if you raise voltages and you also risk damage to the core.
Sent from my Nexus 5 using Tapatalk
lol98lol98 said:
Is there a huge performance boost noticable if you oc the cpu? And what's about the battery life?
Click to expand...
Click to collapse
CPU or GPU? Some users reported less lags (OC GPU) with energy-consuming games.
hi guyz, here is a little video witch looks a not standard demo video, but a real working product with hmp solution (the galaxy tab 10.1 2014 ed)
http://www.youtube.com/watch?v=wYMnu4L2-aU
girl sad it works over the same android solution, so, we could have it in an android 4.3 upgrade, and not only from the 4.4
untill better news, watch the video :good:
iba21 said:
hi guyz, here is a little video witch looks a not standard demo video, but a real working product with hmp solution (the galaxy tab 10.1 2014 ed)
http://www.youtube.com/watch?v=wYMnu4L2-aU
girl sad it works over the same android solution, so, we could have it in an android 4.3 upgrade, and not only from the 4.4
untill better news, watch the video :good:
Click to expand...
Click to collapse
"Android 4.4 can not be just a modified kernel"
Where is it?
I hope samsung this issue as soon as possible:good:
Bilux said:
"Android 4.4 can not be just a modified kernel"
Where is it?
I hope samsung this issue as soon as possible:good:
Click to expand...
Click to collapse
What??m
Sent from my SM-N900 using xda app-developers app
thats really great news hope it comes with 4.4 update
iba21 said:
but a real working product with hmp solution (the galaxy tab 10.1 2014 ed)
Click to expand...
Click to collapse
That's not a 10.1 2014. It's some sort of test device. Look how big the bezels are and how thick it is.
Umh..
Edit: right.. it has a different form factor as the galaxy tab 10.1
zeyadhan said:
thats really great news hope it comes with 4.4 update
Click to expand...
Click to collapse
If samsung wont upgrade the note3.. it will be only a commercial choice.. and sure.. too mouch peoples will disappoint it
iba21 said:
If samsung wont upgrade the note3.. it will be only a commercial choice.. and sure.. too mouch peoples will disappoint it
Click to expand...
Click to collapse
Design, performance, and the thermal profile of Samsung's current Octa devices weren't optimized to run all eight cores at once. Battery life would suffer as could the longevity of some of the components with the additional heat not being able to be properly dissipated. Even if they could activate HMP on existing devices via s/w that doesn't mean they will or that it would be smart. How many mainstream Octa-device owners do you think know or care about HMP?
BarryH_GEG said:
Design, performance, and the thermal profile of Samsung's current Octa devices weren't optimized to run all eight cores at once. Battery life would suffer as could the longevity of some of the components with the additional heat not being able to be properly dissipated. Even if they could activate HMP on existing devices via s/w that doesn't mean they will or that it would be smart. How many mainstream Octa-device owners do you think know or care about HMP?
Click to expand...
Click to collapse
Design performance and thermal profile.. well.. how do you know the thermal profile has issues? Do you have a datasheet?
And.. please.. respond..
The ACTUAL use is the CORE MIGRATION.. traduct for all, 4 cortexA7 at the base.. when touch the screen, in the 99% of the touching situation, cluster switchs from 4 a7 to 4 A15
Why? IKS LOGIC
So.. are you writing a text? Well you are using 4 cortexA15
With hmp the difference is.. an ammount of 4 cortexA7 at the base.. and.. if really necessary, turn on 1-2-3-4 cortexA15
If you look in the video you see angry birds runs over 4 cortexA7, and sometimes turns on the A15 for "other" things..
Well, with the actual cluster migration, in the same situation, game computation is compiled by 4 cortexA15
If you would i can prove it.. i'm on an n900
Well, do you thing 4cortexA7 + SOMETIMES 1-2-3-4 A15 has an HIGHER battery drain than 4 cortexA15?
Because.. when my phone reaches the maxfreq, cpu temperature goes to 80 degreese Celsius in about 4 seconds.. after that thermal ID decreses the maxfreq value..
Well.. the WORST condiction is when there are 4 A15 turned on..
All thinks about hmp as a pure 8 cores with always all 8 cores turned on.. but.. looks at the s800.. does it have the quadcore always turned on??
do you know s800 has an huge heating issue?
With 4 cores at maxfreq (2.3ghz) in about 3 seconds cpu temperature goes to 65 celsius.. after that, maxfreq changes to 1.3-1.5ghz
So.. 4 krait 400 have thermal issues
4 cortex A15 have thermal issues
4 cortexA7 works perfect without any issue
That's the real goal of hmp
Use the cortexA7 for ALL POSSIBLE.. and the other compiled by cortexA15
The 8 core condiction is reached only in heavy benchmarks and "maybe" in heavy games
Web rendering is compiled by A7.. panning needs 1 cortexA15..
So.. do you really think this 5420 has thermal issues?
Well, last stupid question..
The next cpus will have a lower building process, but, will have an higher frequency, so, high consuption caused by high performance arch.. an the 64bit needs more transistors.. so.. more heating issue
How to fix it? An external dissipator with a 120mm fan?
Com'on.. sometimes use the brain
iba21 said:
Com'on.. sometimes use the brain
Click to expand...
Click to collapse
Back at you. You and a bunch of enthusiasts all have their panties in a bunch because one of the two modes Octa runs in isn't being offered by Samsung. There's nothing wrong with the approach they've taken assuming it was to deliver a SoC with comparable performance to Qualcomm's latest chips. With that goal being reached and the right balance between energy efficiency vs. performance already achieved, what reason would Samsung have to, months after the N3 was released, release a feature they could have released at launch? No one but enthusiasts could give a crap about HMP and they make up an estimated 5% of the device population. Samsung builds devices for the mainstream, not enthusiasts. KNOX and eFuse should pretty much confirm that. My logic as to why Samsung chose not to enable HMP and most likely won't until a later generation of Octa chips is released is more based on business logic and common sense than anything else. But you and others keep rationalizing and justifying its imminent appearance via an update. That worked out really well for the SGS4 Octa owners who've been doing the same thing since March.
Oh.. second responce..
With my usage.. i forced the ondemand + my settings + battery saving... why? With this setting the 650mhz (1.3ghz of cortexA7) is the second most freq used.. the first is the 250mhz.. (500mhz of cortexA7)
With this setting i never go over 39 celsius with a normal usage..
Where is the issue?
When i'm writing a text.. cpu increases over the 650mhz.. and.. changes the cluster to A15
So.. for 1 keyboard task.. all 4 cores are used..
The same situation is when i move the web pages, the panning..
With the same situation, with hmp, 4 A7 will used for the most of the things (web rendering too)
And 1 or 2 cortexA15 will used for web panning and keyboard writing
Do you think 4 A7 At maxfreq + 1 A15 at maxfreq has an higher battery drain than 4 A15 at maxfreq??
Oooh.. if i shut down the batterysaving, cortexA15 will be used for the most of the time.. the A7 will.be used only for iper base functions, as like calling and multimedias
so.. if you think it's normal, you should buy one n900 and looks in the kernel sysfs code
BarryH_GEG said:
Back at you. You and a bunch of enthusiasts all have their panties in a bunch because one of the two modes Octa runs in isn't being offered by Samsung. There's nothing wrong with the approach they've taken assuming it was to deliver a SoC with comparable performance to Qualcomm's latest chips. With that goal being reached and the right balance between energy efficiency vs. performance already achieved, what reason would Samsung have to, months after the N3 was released, release a feature they could have released at launch? No one but enthusiasts could give a crap about HMP and they make up an estimated 5% of the device population. Samsung builds devices for the mainstream, not enthusiasts. KNOX and eFuse should pretty much confirm that. My logic as to why Samsung chose not to enable HMP and most likely won't until a later generation of Octa chips is released is more based on business logic and common sense than anything else. But you and others keep rationalizing and justifying its imminent appearance via an update. That worked out really well for the SGS4 Octa owners who've been doing the same thing since March.
Click to expand...
Click to collapse
Are you a flamer?
1) you sad n900 has thermal dissipation problem.. it's as like as on normal people say the sun is cold..
2) Galaxy s4 coudn't have hmp due to a CCI transistor issue.. it means it's impossible to turn on 2 different cluster or system crashes..
3) i don't know why samsung doesen't releases the hmp until.. it's difficult to compile the code, all the scheduler, with the new function.. it's the FIRST TIME in the world.. so.. there aren't any other base code to copy (ex.. ondemand governor was wrote by intel developers.. INTEL..)
4) samsung sad exynos 5420 is ready for hmp.. new exynos versions? Well where do you see those? Post me an official link, not an ipotetic exynos 6xxx with 64bit arch.. because.. i'm rocco siffredi by using words :thumbup:
The only thing witch n900 doesent have is the widcon technology.. only that..
So.. the situation are 2:
1) samsung will release hmp soon for n900
2) samsung will release hmp for galaxy s5 as a marketing pubblicity
Anyway.. n900 has the worst cpu logic.. core migration should be better.. hmp is the maximize of battery saving with the same task
Oooh.. i forgot..
More frequency = more performance = more battery drain = more heat
If i'm using 4 A15 when only 1 is really need.. i'm spending more energy for other 3 A15 FOR NOTHING
Do you think 3 A15 for nothing is what you sad a good battery drain condiction?
Do you think 4 cortexA7 has an higher batterydrain than 3 cortexA15
With hmp i could shut down those 3 A15 and direct use the 4 cortexA7.. with the same performance
With hmp A15 CORES WILL BE USED ONLY IF REAL NECESSARY.. SO.. NO MORE A15 TURNED ON FOR NOTHING
now you understand?
Oh.. why samsung doesen't release hmp from the day 1.. i probably have 1 answer
Since s800 and 5420 has a simillar benchmark results.. 5420 with all 8 core will have more benchmark results
So.. samsung released the s800 version in the most of the world, and the 5420 in the other even if the 5420 should reach an higher benchmark ammount?
Who bought the s800?
Peoples witch wants a slower cpu?
iba21 said:
Are you a flamer?
Click to expand...
Click to collapse
My thanks count is almost three times as high as yours. Why does everyone assume Octa without HMP is broken? 5420 paces S-800 just fine the way it was released. Maybe to pace S-805 we'll see Samsung move to HMP. But for now there's no motive I can see other than placating a bunch of enthusiasts who somehow feel cheated. As for any "marketing" benefit that's a stretch. Do you think 95% of the mainstream that buy a Samsung eight-core phone do so for that reason? If so making the majority of N3's quad-core was a huge mistake. And whether all eight cores running at the same time means anything outside XDA is highly doubtful.
BarryH_GEG said:
My thanks count is almost three times as high as yours. Why does everyone assume Octa without HMP is broken? 5420 paces S-800 just fine the way it was released. Maybe to pace S-805 we'll see Samsung move to HMP. But for now there's no motive I can see other than placating a bunch of enthusiasts who somehow feel cheated. As for any "marketing" benefit that's a stretch. Do you think 95% of the mainstream that buy a Samsung eight-core phone do so for that reason? If so making the majority of N3's quad-core was a huge mistake. And whether all eight cores running at the same time means anything outside XDA is highly doubtful.
Click to expand...
Click to collapse
Other "majority" with a quadcore s800 only because s800 has LTE in the SoC
Qualcomm sells his s800 at less than double than the single LTE chip
Would you buy a top range phone without lte in states witch have it?
Anyway from heating issue to marketing choice.. well.. if it's only a marketing choice, i have to say fu samsung
Simply, i hope to use my exynos with it's own completely tech.. 5420 has the ability to do..
iba21 said:
Are you a flamer?
1) you sad n900 has thermal dissipation problem.. it's as like as on normal people say the sun is cold..
2) Galaxy s4 coudn't have hmp due to a CCI transistor issue.. it means it's impossible to turn on 2 different cluster or system crashes..
3) i don't know why samsung doesen't releases the hmp until.. it's difficult to compile the code, all the scheduler, with the new function.. it's the FIRST TIME in the world.. so.. there aren't any other base code to copy (ex.. ondemand governor was wrote by intel developers.. INTEL..)
4) samsung sad exynos 5420 is ready for hmp.. new exynos versions? Well where do you see those? Post me an official link, not an ipotetic exynos 6xxx with 64bit arch.. because.. i'm rocco siffredi by using words :thumbup:
The only thing witch n900 doesent have is the widcon technology.. only that..
So.. the situation are 2:
1) samsung will release hmp soon for n900
2) samsung will release hmp for galaxy s5 as a marketing pubblicity
Anyway.. n900 has the worst cpu logic.. core migration should be better.. hmp is the maximize of battery saving with the same task
Click to expand...
Click to collapse
any idea if the octacore version for mediatek helps.. ie. if they releases the source for hmp?? may be jus a noobish question :silly:
cooldoc007 said:
any idea if the octacore version for mediatek helps.. ie. if they releases the source for hmp?? may be jus a noobish question :silly:
Click to expand...
Click to collapse
Hard to say. Their using eight identical A7 chips which makes task migration and scheduling easier.
For the cores MediaTek has opted to use eight Cortex-A7 cores arranged in a big.LITTLE configuration. Which doesn’t make much sense as big.LITTLE is meant to be for a true Heterogeneous Multi-Processing design where some of the cores are faster (i.e. Cortex-A15 cores) than others. It seems that MediaTek has arranged the eight cores in a kind of little.LITTLE arrangement. In this arrangement MediaTek is using its own scheduling algorithm that also monitors temperature and power consumption to ensure optimum performance at all times.http://www.androidauthority.com/mediatek-mt6592-318700/
cooldoc007 said:
any idea if the octacore version for mediatek helps.. ie. if they releases the source for hmp?? may be jus a noobish question :silly:
Click to expand...
Click to collapse
Mediatek uses all the same cluster as octa, it means scheduling doesen't have to switch and chose what core need.. simply.. it's a false big.little.. because it's a little.little!
Probably there are 2 clusters in the core.. and the scheduling logic probably is this:
First case..
there are 1 cluster (4 cortexA7) always on.. the second shutted down by power gating tech.. when scheduling needs more power.. turn on the second cluster
Second case..
All cores are indipendently, so, in the base situation 1 core on and the other shutted down..
When scheduler needs more power.. it activates the other core..
But.. for me the first case will be used.. it's easier to write the code..
###########
Some free informations about big.little tech
###########
Big.little has 2 clusters
http://www.imgur.com/amCLDKU.png
If you open the terminal, and you write:
cat /sys/devices/system/b.L/b.L_core_stat
You'll see what cluster are on.. and.. if you red what i wrote.. you'll see in the 99% of case the A15 cluster..
In that stat you see 0 and 1.. 0 is shutted down, 1 is on..
If you see there are the L2 value too.. 2 clusters has 2 different L2 (cache second level), so, cache is shutted down too..
A7 Cluster has 512kb of cache.. A15 has 2048kb of cache (2mb) (4 time more)
Cache absorbs a lot of energy.. that's one of the cause of the low power consuption by a7 arch..
Well, how to shut down the cluster?
Big.little uses the power gating tech, it's created by intel, and, simply, when there aren't an usage of the core, chip AUTOMATICALLY shut down it..
The old logic uses a dvfs command to say to the chip to shut down the core.. now it's all absolutely automatically.. so.. if scheduler doesen't want to send a taks in one core.. that core will be shutted down until one scheduling call
What's the scheduler?
linux kernel has this code in it witch chose the task destination..
How it work?
It runs the task for little time (ex.. 10milliseconds) and looks about the usage of the cpu.. it trys to find the possible cpu load caused by that task, and it move it into one core witch can compile it without increasing frequency..
So.. the base logic is to always have the minor freq possible
Why?
More freq = more and more power consuption
one chip at 500mhz absorbs less than an half than the same chip at 1000mhz
so.. 4 cores at 500mhz are better than 1 at 2ghz.. absorbs less energy and have the same base computation
Sure.. scheduler is not a mage, it can't be perfect, and sometimes it moves the task in the worst core.. it means, the worst situation for energy efficiency
Anyway.. the actual cluster migration logic chose from 2 cluster.. you could have OR 4A7 OR 4A15
why? Code is easyer to write..
android scheduler is the same as normal scheduler.. there are only an IKS (in kernel switching) module witch chose what cluster use..
From 250mhz to 650mhz there is used A7 cluster
From 700mhz to 1900mhz there is used A15 cluster
Frequency of A7 cluster is an half of the real freq of the chip
So.. 250mhz in kernel value means 500mhz of the chip a7 cluster.. 650mhz of kernel means 1300mhz of the cluster (650 x 2)
A15 has the same frequency as kernel.. so.. 800mhz is really 800mhz..
There are 2 BIG BUGS with that logic:
1) scheduler doesen't have a good code.. it sees 4 cores.. so.. it moves tasks in those 4 cores.. the IKS is indipendent out of the scheduler logic.. so.. there are not so mouch time witch one core has NO LOADING.. so.. the most of the time if the cluster is turn on, all cores are really on
2) it's the conclusion of the first case.. when the A15 are turned on.. A7 are off.. and.. if all tasks force all 4 A15 cores to be active, frequency grow up for all 4 cores.. and.. you have to know that cortexA15 has an HIGH POWER DISSIPATION..
IT REALLY NEEDS A PHYSICAL DISSIPATOR + A FAN AS LIKE PC
In simple words.. the actual cluster migration logic USES TOO MOUCH THE A15 CLUSTER FOR NOTHING..
A car example.. you use the car in a normal street with a low (2nd) gear at 6000rpm at 80km/h (50miles/h)
You'll have an high fuel consuption for nothing
You could increase the gear (5th) and engine will slow down at, for ex, 2000rpm with the same 80km/h
That's a real efficiency
We actual use too mouch cortexA15 cores for nothing.. it means.. spend energy for nothing
The HMP REWRITES THE SCHEDULING LOGIC..
Scheduler knows what are the cores and what architecture have.. so.. the base situation is 1 A7 core.. all other shutted down..
It runs a task in A7 core, looks of it "size", and move into one other A7 core (if size is low) or in one A15 cores (if size is high)
So.. this logic is completely different.. now the scheduler uses less cores as possible, and prefere A7 cores over A15 if they could run the task
Scheduling has a better powergating code.. so.. it choses to turn on one core OR increase frequency of the core..
I did some examples in other posts
Anyway.. HMP tryes to use A7 in the most of the condictions, and, moves sometimes some tasks in 1-2-3-4 A15 cores dipendent of the condiction
I repeat one simple example
CLUSTER MIGRATION (ACTUAL)
touch the screen, 4 A15 on
Web rendering (loading) 4A7 on (in the most of the case)
Web page panning (sliding) 4A15 on
HMP
Tuch the screen 4 A7 on and SOMETIMES one A15
Web rendering 4 A7 on and SOMETIMES 1-2 A15 ON
Web page panning 4A7 on and 1-2 A15 on..
Why in hmp always 4 A7 on?
Because OS has a lot of tasks to do.. low tasks (as like sensors) are compiled by A7.. and huge tasks by A15
In the actual cluster migration, if you reach more than 650mhz (always if you need to compile 1 stupid high task) all 4 A15 are on even to compile other stupid tasks.. so.. 1huge task increases the power consuption for all other 300 little tasks
With HMP.. 300 little tasks are compiled by A7 cluster.. and 1 huge by 1 A15 cluster
THAT'S WHAT I CALL EFFICIENCY
Sure.. more efficiency = less energy drain = less cpu heating
Sorry for my kilometrical post.. i hope someone read it, and understand what are the benefit of this "code"
iba21 said:
Mediatek uses all the same cluster as octa, it means scheduling doesen't have to switch and chose what core need.. simply.. it's a false big.little.. because it's a little.little!
Probably there are 2 clusters in the core.. and the scheduling logic probably is this:
First case..
there are 1 cluster (4 cortexA7) always on.. the second shutted down by power gating tech.. when scheduling needs more power.. turn on the second cluster
Second case..
All cores are indipendently, so, in the base situation 1 core on and the other shutted down..
When scheduler needs more power.. it activates the other core..
But.. for me the first case will be used.. it's easier to write the code..
###########
Some free informations about big.little tech
###########
Big.little has 2 clusters
http://www.imgur.com/amCLDKU.png
If you open the terminal, and you write:
cat /sys/devices/system/b.L/b.L_core_stat
You'll see what cluster are on.. and.. if you red what i wrote.. you'll see in the 99% of case the A15 cluster..
In that stat you see 0 and 1.. 0 is shutted down, 1 is on..
If you see there are the L2 value too.. 2 clusters has 2 different L2 (cache second level), so, cache is shutted down too..
A7 Cluster has 512kb of cache.. A15 has 2048kb of cache (2mb) (4 time more)
Cache absorbs a lot of energy.. that's one of the cause of the low power consuption by a7 arch..
Well, how to shut down the cluster?
Big.little uses the power gating tech, it's created by intel, and, simply, when there aren't an usage of the core, chip AUTOMATICALLY shut down it..
The old logic uses a dvfs command to say to the chip to shut down the core.. now it's all absolutely automatically.. so.. if scheduler doesen't want to send a taks in one core.. that core will be shutted down until one scheduling call
What's the scheduler?
linux kernel has this code in it witch chose the task destination..
How it work?
It runs the task for little time (ex.. 10milliseconds) and looks about the usage of the cpu.. it trys to find the possible cpu load caused by that task, and it move it into one core witch can compile it without increasing frequency..
So.. the base logic is to always have the minor freq possible
Why?
More freq = more and more power consuption
one chip at 500mhz absorbs less than an half than the same chip at 1000mhz
so.. 4 cores at 500mhz are better than 1 at 2ghz.. absorbs less energy and have the same base computation
Sure.. scheduler is not a mage, it can't be perfect, and sometimes it moves the task in the worst core.. it means, the worst situation for energy efficiency
Anyway.. the actual cluster migration logic chose from 2 cluster.. you could have OR 4A7 OR 4A15
why? Code is easyer to write..
android scheduler is the same as normal scheduler.. there are only an IKS (in kernel switching) module witch chose what cluster use..
From 250mhz to 650mhz there is used A7 cluster
From 700mhz to 1900mhz there is used A15 cluster
Frequency of A7 cluster is an half of the real freq of the chip
So.. 250mhz in kernel value means 500mhz of the chip a7 cluster.. 650mhz of kernel means 1300mhz of the cluster (650 x 2)
A15 has the same frequency as kernel.. so.. 800mhz is really 800mhz..
There are 2 BIG BUGS with that logic:
1) scheduler doesen't have a good code.. it sees 4 cores.. so.. it moves tasks in those 4 cores.. the IKS is indipendent out of the scheduler logic.. so.. there are not so mouch time witch one core has NO LOADING.. so.. the most of the time if the cluster is turn on, all cores are really on
2) it's the conclusion of the first case.. when the A15 are turned on.. A7 are off.. and.. if all tasks force all 4 A15 cores to be active, frequency grow up for all 4 cores.. and.. you have to know that cortexA15 has an HIGH POWER DISSIPATION..
IT REALLY NEEDS A PHYSICAL DISSIPATOR + A FAN AS LIKE PC
In simple words.. the actual cluster migration logic USES TOO MOUCH THE A15 CLUSTER FOR NOTHING..
A car example.. you use the car in a normal street with a low (2nd) gear at 6000rpm at 80km/h (50miles/h)
You'll have an high fuel consuption for nothing
You could increase the gear (5th) and engine will slow down at, for ex, 2000rpm with the same 80km/h
That's a real efficiency
We actual use too mouch cortexA15 cores for nothing.. it means.. spend energy for nothing
The HMP REWRITES THE SCHEDULING LOGIC..
Scheduler knows what are the cores and what architecture have.. so.. the base situation is 1 A7 core.. all other shutted down..
It runs a task in A7 core, looks of it "size", and move into one other A7 core (if size is low) or in one A15 cores (if size is high)
So.. this logic is completely different.. now the scheduler uses less cores as possible, and prefere A7 cores over A15 if they could run the task
Scheduling has a better powergating code.. so.. it choses to turn on one core OR increase frequency of the core..
I did some examples in other posts
Anyway.. HMP tryes to use A7 in the most of the condictions, and, moves sometimes some tasks in 1-2-3-4 A15 cores dipendent of the condiction
I repeat one simple example
CLUSTER MIGRATION (ACTUAL)
touch the screen, 4 A15 on
Web rendering (loading) 4A7 on (in the most of the case)
Web page panning (sliding) 4A15 on
HMP
Tuch the screen 4 A7 on and SOMETIMES one A15
Web rendering 4 A7 on and SOMETIMES 1-2 A15 ON
Web page panning 4A7 on and 1-2 A15 on..
Why in hmp always 4 A7 on?
Because OS has a lot of tasks to do.. low tasks (as like sensors) are compiled by A7.. and huge tasks by A15
In the actual cluster migration, if you reach more than 650mhz (always if you need to compile 1 stupid high task) all 4 A15 are on even to compile other stupid tasks.. so.. 1huge task increases the power consuption for all other 300 little tasks
With HMP.. 300 little tasks are compiled by A7 cluster.. and 1 huge by 1 A15 cluster
THAT'S WHAT I CALL EFFICIENCY
Sure.. more efficiency = less energy drain = less cpu heating
Sorry for my kilometrical post.. i hope someone read it, and understand what are the benefit of this "code"
Click to expand...
Click to collapse
I really enjoy reading your explanations and learning about HMP.
I hope Samsung realeases this for the exynos variant of the Note 3.
2 examples :
http://www.imgur.com/vmXPhNx.png
Normal status.. nothing open.. only system tuner.. airplane mode.. ALWAYS 4 CORTEXA15 on
http://www.imgur.com/P2HFAxp.png
Same condiction with maxfreq of 650mhz (1.3ghz of cortexa7)
More apps opened, no airplane mode.. ALWAYS CORTEXA7
....
Why?
When i touch the screen to press the run button, cpu goes over 650mhz and switch to cortexA15.. after that come back..
If i force maxfreq to 650mhz.. iks can't switch to cortexA15
It's the opposite of hmp solution! Ahahahahaha
Now it's easyer to understand?
That's why i need it..
If you woukd do the same test.. download system tuner and run that string in terminal.. you'll see
After that, if you have root.. go to CPU tab, move maxfreq to 650mhz.. and redo terminal command.. you'll have the same results as mine!!
This is and this will be until hmp upgrade (only kernel upgrade)
Sure.. i remember, more time in A15 = more energy absorb = more heat..
Now.. open this video
https://www.youtube.com/watch?v=wYMnu4L2-aU&feature=youtube_gdata_player
And look.. guy press the hone button.. 4A7 on + 1 A15 for 500ms..
Do you think 4A7+ 1A15 absorbs more energy than 4A15?
Well.. SAMSUNG PLEASE RELEASE HMP
Hi, If you use yuphoria in a non-ac environment in India in summer where outside temperature is easily between 35-40 degree Celsius, your ear and nearby head area start hurting. Its a very dangerous, as it can cause permanent damage to ears or head.
Now before anyone say, common its a smartphone, it will heat up in such temperature, its normal, I would like to inform you, when I use my father's moto E3 power in same environment I don't feel any heat.
So obviously there is some problem with Yuphoria. consider this, your phone is sitting ideal from past one hours, a call comes, you pic the call, talk for 15 minutes and then you can feel that the screen is warm in the top right corner. you are not playing any game, doing nothing which involves heavy cpu processing, you are just taking a call for 15 minutes.
You should not feel any discomfort by doing this if mobile is Ok, as proved by moto E3 power. So something is seriously wrong with yuphoria.
So I tried to search the net to know the reason why yuphoria is overheating and came across useless advice, like stop the running processes , use different charger etc (I mean basic stuffs), but my question was still unanswered , why motoE3 power is cool even if other apps are running and yuphoria is not.
In my experiment I came across one very interesting observation which is not discussed anywhere, so here I am presenting the real cause of yuphoria's heating problem.
If we see the cpu usage using CPU-Z app in moto E3 power when no other application is running, we can find that its 201 MHz for single core most of the time. This I have checked in moto E3 power having stock ROM and data connection off. I am attaching here screenshot.
https://ibb.co/ddCmLF
If we do the same thing with Yuphoria , it never goes below 800 MHz. here are the screenshots of Yuphoria CPU usage and governors selected
https://ibb.co/bUJyZa
here is the governors
https://ibb.co/iCJXua
So obviously Yupohria CPU is always running at higher frequency than Moto E3power .
FURTHER MOTO E3 POWER HAS METAL PLATS ATTACHED TO PROCESSOR TO ACT AS HEAT SINK. you can check out the disassembling video of yuphoria and moto e3 power on youtube to see that moto e3 power has heat sink whereas yuphoria doesn't have it.
Moto E3 power is using mediatek processor which produces less heat and also the highest frequency of Moto E3 Power is less, still they included a heat sink in moto e3 power.
yuphoria is using more heat producing snapdragon 410 processor, still the engineers have not included heat sink. why yuphoria ? why?
I experimented by setting minimum cpu frequncy to 200 MHz and using powersave governor and found that now I can take calls without any heating issue. Remember still in this case yuphoria is using 3 cores with 200 Mhz frequency where as moto e3 power is using only one core with 201 MHz.
now I understand that moto E3 power is running on stock and my yuphoria is running on RR Rom, but I used to feel same heating problem even when my mobile was on original cyanogen ROM, so I think this problem of processor not going below 800 MHz is present even in original cyanogen ROM of yuphoria.
Now I want to know from all the technical experts here, why yuphoria's cpu is not going below 800 Mhz even when no other app is running. Is it the limitation of snapdragon 410 processor and nothing can be done about it, or it depends upon kernel and flashing another kernel or ROM will solve the issue.
obviously we don't want to use powersave governor with 200 MHz setting, otherwise what's the point of buying a 1.21 Ghz processor mobile. We want it to use minimum frequency that 200 single core when no other application is running and using higher frequency only when required like moto E3 power.
Is it possible? If yes , how?
I am also curious to know why they decided to not include heat sink in yuphoria?
I am not a technical expert but i don't think 800mhz might be a limitation of snapdragon 410.
Plus with ur experiment results i think it might be actually software flaw and with custom kernel or a custom rom which gives the ability to choose min and max speeds should fix it as u can choose min to 200mhz even with other governors.