bit.LITTLE processor solution possible? - Nexus 4 Q&A, Help & Troubleshooting

Considering the big.LITTLE processors that'll be coming out in the future and the way they work, i.e. using ARM a7 for processes that require little processing power and switching to a15 cores for high processing power requirements.
Is it possible, to create a kernel that emulates this with current quad core processors? With the most basic implementation being 2 cores underclocked to something around 800mhz and the other 2 either overclocked or kept the same. Would a cpu governor need to be modified to properly control the clocks and activations of the cores?

Related

Sony experia Z ONLY QUAD-CORE 1.5GHZ ??

So I've been noticing somethin strange other then the experia z every single other high end device that will come out as of 2013 will be using a 1.7GHZ snapdragon the only high end device that will use a lower one is experia z why????? I mean the phone hasn't come out yet can't they just put the 1.7GHZ instead? why use a lower one 1.5GHZ from phones of the fourth quarter of 2012 its old tech!!!
Sent from my SCH-I510 using xda app-developers app
Calm down man, 1.5GHz quadcore is good for Android. Android really doesn't need such a high speeds
And CPU clock doesn't mean smoother device
Sent from my LT26i using xda app-developers app
1.5Ghz Quad Core is not "only". And they all use exactly the same CPU which operates with 1,5-1,7Ghz speed. Clock speed isn't everything. Look at the iPhone - it uses dual core 1.2Ghz CPU - yet its performance is 5 times smoother than most quad core devices...
Dual core is more than enough for anything a smartphone might need to do - as long as you put good software on it.
gabrielpina4 said:
So I've been noticing somethin strange other then the experia z every single other high end device that will come out as of 2013 will be using a 1.7GHZ snapdragon the only high end device that will use a lower one is experia z why????? I mean the phone hasn't come out yet can't they just put the 1.7GHZ instead? why use a lower one 1.5GHZ from phones of the fourth quarter of 2012 its old tech!!!
Sent from my SCH-I510 using xda app-developers app
Click to expand...
Click to collapse
Seriously? "Only" on a quad core 1.5ghz CPU for a smartphone? What are you gonna run on your phone that would require you more? Or do you just want your battery to drain more for no possible reasons? Some users even just underclock for the sake of saving battery.
If you ask me I buy this because of the features and the RAM not because of processor clock.
If you ever let me choose I would rather go for a 1ghz dual core processor with 4GB RAM than having a 2ghz quad core processor with 2GB RAM.
The only reason why I would want the Qualcomm S4 Pro processor is because of adreno 320.
A dual core is good enough dude .. this is a quad core lol
Sent from my GT-N7000 using xda premium
No offense but you just sound like your trolling. Same goes for your other thread too
AK4TAY7BEN said:
No offense but you just sound like your trolling. Same goes for your other thread too
Click to expand...
Click to collapse
I agree. I think he's trolling.
Riyal said:
Seriously? "Only" on a quad core 1.5ghz CPU for a smartphone? What are you gonna run on your phone that would require you more? Or do you just want your battery to drain more for no possible reasons? Some users even just underclock for the sake of saving battery.
If you ask me I buy this because of the features and the RAM not because of processor clock.
If you ever let me choose I would rather go for a 1ghz dual core processor with 4GB RAM than having a 2ghz quad core processor with 2GB RAM.
The only reason why I would want the Qualcomm S4 Pro processor is because of adreno 320.
Click to expand...
Click to collapse
What would be the purpose of 4GB of RAM in a smartphone are you running Photoshop or a VM? Where did this stigma that more cores is equivalent to less efficient power use. More asynchronous cores allow for more accurate scaling of processing power to needs, thus higher power efficiency because the CPU spends less time in higher power states.
REAVER117 said:
What would be the purpose of 4GB of RAM in a smartphone are you running Photoshop or a VM? Where did this stigma that mire cores is equivalent to less efficient power use. More asynchronous cores allow for more accurate scaling of processing power to needs, thus higher power efficiency because the CPU spends less time in higher power states.
Click to expand...
Click to collapse
Buddy android runs Dalvik VM and our GPU uses dedicated RAM for processing certain graphic tasks. So yes we are running a VM on our mobile phones.
Also with a proper monitoring app you could see for yourself which uses more and needs more resource here. whether processing or memory.
Didn't you even wonder why our phones consume almost 700mb RAM without even a single foreground application open? Yet it sits idle in a single core and remains in between 400mhz+ to 900mhz?
Also I didn't say that more cores consumes more power in my statement but still since each core requires power to run it should also consume more. Also I didn't mention anything about number of core I was talking about the clocks. Since the higher the clock requires more Amperes. Still underclocking your phone by 500mhz would prolly just save about 2% of your battery anyways.
you don't need higher cpu clock to get a pocket heater for this winter
My Optimus G has the same cpu an the thermal throttling is kikin in pretty fast. This 1.7Ghz S4pro will thermal throttle as fast or even faster, rendering numerical advantage meaningless.
I don't want to feed the troll but I also think dual core is good enough.
Riyal said:
Buddy android runs Dalvik VM and our GPU uses dedicated RAM for processing certain graphic tasks. So yes we are running a VM on our mobile phones.
Also with a proper monitoring app you could see for yourself which uses more and needs more resource here. whether processing or memory.
Didn't you even wonder why our phones consume almost 700mb RAM without even a single foreground application open? Yet it sits idle in a single core and remains in between 400mhz+ to 900mhz?
Also I didn't say that more cores consumes more power in my statement but still since each core requires power to run it should also consume more. Also I didn't mention anything about number of core I was talking about the clocks. Since the higher the clock requires more Amperes. Still underclocking your phone by 500mhz would prolly just save about 2% of your battery anyways.
Click to expand...
Click to collapse
I have yet to see my Xperia ZL have less than 800MB of free an extra 2GB would be a total waste. And you simply stated you'd rather have a dual than a quad, peak frequency means very little except for potential processing power. Just because your CPU is capable of a higher clock speed doesn't mean it will idle any higher. Likewise the only difference between a quad with a single utilized core and a dual with a single utilized core is the minute amount if extra leakage current for the quad.
I think you meant to say that higher frequencies may need more voltage, amperage has very little to do with CPU frequency scaling.
And obviously the memory overhead for a virtualized process i.e. Dalvik VM is not even in the same league as a system VM.
REAVER117 said:
I have yet to see my Xperia ZL have less than 800MB of free an extra 2GB would be a total waste. And you simply stated you'd rather have a dual than a quad, peak frequency means very little except for potential processing power. Just because your CPU is capable of a higher clock speed doesn't mean it will idle any higher. Likewise the only difference between a quad with a single utilized core and a dual with a single utilized core is the minute amount if extra leakage current for the quad.
I think you meant to say that higher frequencies may need more voltage, amperage has very little to do with CPU frequency scaling.
And obviously the memory overhead for a virtualized process i.e. Dalvik VM is not even in the same league as a system VM.
Click to expand...
Click to collapse
Buddy that 800mb is without running any foreground applications other than either Settings app or the homescreen. Like I said try running some monitoring apps on the background and try using the browser then maybe try loading some sites with lots of javascript codes in it.
Or if you like try launching 4 types of angry birds and the 2 temple run games simultaneously without killing one of them and let's see if OOM doesn't kick in and kill any of them.
Regarding CPU cores please state something that requires a quad core processor. The smoothness of the UI your experiencing is because of the type of processor your phone is using "The Snapdragon S4 Pro" even if you disable all the extra cores in it you won't feel anything different unless of course you'll run some benchmark tools or video decoding stuffs in there.
And just FYI more cores doesn't mean greater processing power. It's more cores = more processes it can handle.
And on the CPU freq clocks who said t that amperes doesn't increase on each frequency table? Please take a look at qualcomm's document on their site regarding it's processors so you would know how they calculate it. Voltage is just used to provide more electricity to power up the processor but voltage alone won't make a processor active.
This discussion is going to the wrong way.
Thread closed.

[Q] apps that monitor cpu

Anyone knows why all apps i downloaded (cpu-z, monitor cpu, setcpu) only show max mhz at 1300?
i have a sm-g900h with arm15 cortex r2p3 , i understand that is an octa core with 4 cores at 2.1 ghz and 4 at 1.5
It is a phone problem or all these app don´t support the system?
mrrombys said:
Anyone knows why all apps i downloaded (cpu-z, monitor cpu, setcpu) only show max mhz at 1300?
i have a sm-g900h with arm15 cortex r2p3 , i understand that is an octa core with 4 cores at 2.1 ghz and 4 at 1.5
It is a phone problem or all these app don´t support the system?
Click to expand...
Click to collapse
It's likely most app do no "fully" support this new octa-core. I would suspect they only show the little CPU 4 cores @ 1.5GHz, however seeing 1.3GHz as the max is weird. In S4 octa-core, the max frequencies was used by both CPUs and frequencies below 600Mhz where meant to be used by little core (600Mhz being 1.2GHz on the little CPU, 700Mhz being exactly that on the big CPU), so there might be some similar tricks on the new S5. This would mean the kernel would only show 4 cores at any point in time.
Have you tried Android Tuner, it can adapt to any number of cores automatically (a little down arrow allows to switch to multi-core control) ? If you try it, can you post a screenshot here? I intend to buy the Galaxy S5 with 8 cores for testing purposes, so I'd be interested by first-hand screenshots, if any. You can check and post screenshots of the main CPU tab and also the Times tab which will show available cores timings for each frequencies.

GS7 Edge Processor

So the Qualcomm Snapdragon 820 is quad core. Why did Qualcomm decide to go with a quad core one over a octacore or hexacore? How would that affect the GS7/GS7 Edge if it were octacore or hexacore? How much of a difference is there between the Exynos and 820?
Indeed the snapdragon 820 is a quad core SOC unlike most recent socs which have featured 8 cores (2 clusters of 4 cores). However most big.little socs like the exynos 8890 and 7420 use 4 low power slow processors and 4 high power, but power hungry processors. They are completely different architectures. This means that while the exynos 8890 for instance has 8 cores. Only 4 of them are really designed for performance. The other 4 are designed to save power. The 820 is different. It's also some sort of big.little setup with 2 clusters of 2 cores. However both clusters are identical architectures. The difference is one cluster is clocked lower and has a different l2 cache configuration in order to use less power. On top of that the custom cores in the 820 are faster per core than the exynos 8890. So clock for clock the 820 would win against the high power cluster of the exynos. In heavily multitheaded situations though. The exynos still can tap into all 8 cores at the same time which should give it an advantage in that scenario. For the rest of the time I would imagine the 4 faster cores of the snapdragon would be better suited to everyday stuff. As for why they only went with 4. My guess is cost, and power efficiency. Kyro is a brand new architecture. Krait went through many iterations. Kyro will probably see a noticeable reduction in its power envelope in the next iteration which would make shoving more of them onto an SOC a more viable option. As for gpu, all signs are pointing to the snapdragons adreno GPU beating the Mali in the exynos atm. Development will also be improved on the snapdragon device as Qualcomm releases the proprietary vendor binaries and Samsung does not. This means the likelihood of seeing cm or aosp on an exynos variant is slim. Hope this helps!
Actually, the Kryo cores are (slightly) better at running single threaded tasks while the Exynos cores are (slightly) better at running multi-threaded tasks. I doubt the everyday users will notice.
The Adreno is also more powerful than the MALI GPU, though everyday users will mostly notice a performance improvement on applications using the Vulkan API vs regular applications, than anything between both these GPUs.
Finally the memory management seems much better on the Exynos 8890 for some reason (about twice as fast), since the same chips are used I wonder whether it's a software or a hardware implementation difference, both units are plenty fast though.
The real difference between both these SOCs will seen in the power management efficiency, in fact both variants are overpowered in every aspects as far as regular usage goes, so there is little point in comparing which one's the fastest. Instead, you need to wonder which one is the most conservative with power consumption while achieving equivalent performances.
Both the GPUs on these SOCs support the Vulcan API. And, whilst the Adreno is faster in terms of pure benchmark numbers, I very much doubt there will be a noticeable difference on any game or application, Vulcan or otherwise, that will be released during the lifetime of these phones.
Yeah, that does help explain it. Thanks. I just hoped there wouldn't be a TSMC vs Samsung difference in the iPhone 6S/6S Plus SoC.
i was thinking 8 core snapdargon 810 was over heating and thermal throttling so they went for 4 cores instead on snapdragon 820.
just my thoughts.

Hotplugging & big.LITTLE cores

Guys,
Wondering could ye help me. I was wondering has anyone tried shutting off the LITTLE cores and turned our phone into a quad big core? Maybe get it to act like a slower 820?
Correct me if I'm wrong but would it not be faster, more efficient and cooler to have 4 big cores that are heterogeneous computing compatible? Rather than, 4 LITTLE cores do everything and then when we want to game etc, the big cores turn on but because it's 8 cores it thermal throttles then were left with the abysmal performance of the LITTLE cores?

Big Core are "stopped"

hi
i am new but i cant find a way for see the firtst 1,5 ghz cores work....all cpu app i can find see me only work the last 4 core with 1,2 ghz...
please help me unlock the firt 4 core are everytime stopped thnx for help
Those kick in only when you are doing something "hard" in that time. Like benchmarking in background.
SoNic67 said:
Those kick in only when you are doing something "hard" in that time. Like benchmarking in background.
Click to expand...
Click to collapse
i try run all test and i dont see one time the big core work, they are stopped every time...( try pc mark but dont work he crash after 4k encoding video) with kernel auiditior i can active all 8 core...now they work everytime and i can set governor for each processor...
but other app like cpuz dont find the first processor they see only the last 4 core... ok maybe with bench i can see all cores work but is very hard find a way for check the correct work for governor and the phone processor work fine....
if u dont have root cpu app dont find any governor...or see only one processor...
Those are limitations of the apps themselves or your OS.
I have the official N (rooted with ElementalX) and CPU-Z sees all the cores.
Also there are never supposed to work all 8 in the same time, only a group/cluster of 4 at one time, it is not a straight-up 8 core CPU. They are not "equal" in respect of performance: https://en.wikipedia.org/wiki/ARM_big.LITTLE
Different combinations of Governors and Schedulers produce different results.
PS: The newer Snapdragon 625, that is present in G5 Plus, is listed as a true 8 core: https://www.qualcomm.com/products/snapdragon/processors/625
The 617 is a big.LITTLE octa-core, not a true 8-core CPU such as the 625, like @SoNic67 said. The 617 has one cluster running up to 1.5-1.6 GHz (depending on the kernel), and one cluster that generally runs from 500 MHz-1200 MHz.
The little cluster, or the 500-1200 MHz cluster, is fine for basic tasks, such as UI, scrolling, etc. However, in games, all cores will online (or at least that's the point). Some apps are not threaded for 8 cores and thus will not utilize, or need, 8 cores.
Also, in reality, the 4 "big" cores make very little difference in terms of performance. I did 2 benches in another thread, where Antutu came up 40K with 4 cores and 45k with 8 cores. Although this seems like a large performance decrease, without the big cores the phone was cool, still ran quick, and drained far less battery.
Finally, having 8 cores also can introduce performance deficits as well, especially if your hotplug is inefficient (there may be delays in turning on cores, resulting in UI jank). I thus recommend simply leaving them off- better battery, cooling, and still decent performance.
thx for support and continue OS is amazing gw.
negusp said:
The 617 is a big.LITTLE octa-core, not a true 8-core CPU such as the 625, like @SoNic67 said. The 617 has one cluster running up to 1.5-1.6 GHz (depending on the kernel), and one cluster that generally runs from 500 MHz-1200 MHz.
The little cluster, or the 500-1200 MHz cluster, is fine for basic tasks, such as UI, scrolling, etc. However, in games, all cores will online (or at least that's the point). Some apps are not threaded for 8 cores and thus will not utilize, or need, 8 cores.
Also, in reality, the 4 "big" cores make very little difference in terms of performance. I did 2 benches in another thread, where Antutu came up 40K with 4 cores and 45k with 8 cores. Although this seems like a large performance decrease, without the big cores the phone was cool, still ran quick, and drained far less battery.
Finally, having 8 cores also can introduce performance deficits as well, especially if your hotplug is inefficient (there may be delays in turning on cores, resulting in UI jank). I thus recommend simply leaving them off- better battery, cooling, and still decent performance.
Click to expand...
Click to collapse

Categories

Resources