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What EXACTLY is VM heap & what does it do?

What EXACTLY is VM heap & what does it do?

It's the largest chunk of memory that a single instance of an application (ran through the Dalvik VM) can obtain. There's also a corresponding minimum setting. It works much the same way as passing the Xmin and Xmax parameters to a java VM when launching it from the command line.

relative to battery life?
Thats awesome...thx for responding!
*Does the size of the VM heap have an effect on battery life? If yes then how?

ups2525 said:
Thats awesome...thx for responding!
*Does the size of the VM heap have an effect on battery life? If yes then how?
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My brain tells me yes, a little, through logic.
If it can utilize more memory, that means more information passing through more locations, but it shouldn't be to significant.
You messing around in your build.prop?
I took a peak at mine last night, and the heap is set at 64m in unl3ashed, or blurred, or whatever th3ory is calling his rom now.

Virtual Machine heap most directly influences battery life in terms of how often your phone will perform what's called 'garbage collection', or trimming your apps' memory usage.
A higher heap size means an app can use more space before getting cut, so it can improve your battery life a little bit as garbage collection uses CPU and thus battery. It *can* negatively impact the performance of smaller apps as it will allow the more demanding ones to 'hog' your memory resources. On a superphone like the Bionic it's not likely to hurt, but on, say, a Galaxy S (or the Charge, which I came from) with 512MB of RAM, 120mb of which was actually user accessible, it made a difference.
Short version: with a phone with 1GB of RAM, higher is *probably* better for battery life and won't have much impact on performance. YMMV.

Vm heap tool is a great app to use to experiment with heap sizes if you are rooted. Check it out
Sent from my DROID BIONIC using XDA App

Thx!
Thanks for the breakdown guys...

Apps Performance issue

Hello evry one. I have problem in my captivate and other models of android. I installed almost every custom rom but problem of loading apps fast still exist. What i mean is.. that when i on my mobile, so first time apps like calender, messenging etc take a little time to load. than when i close the app and open again, it loads very quickly. When mobile goes to standby for more than 10 mins, and when i on it, it again take little time to load apps, and widget menu etc.
Why it is like that ??? and whats the solution to always load the apps quickly

majidshahab091 said:
Hello evry one. I have problem in my captivate and other models of android. I installed almost every custom rom but problem of loading apps fast still exist. What i mean is.. that when i on my mobile, so first time apps like calender, messenging etc take a little time to load. than when i close the app and open again, it loads very quickly. When mobile goes to standby for more than 10 mins, and when i on it, it again take little time to load apps, and widget menu etc.
Why it is like that ??? and whats the solution to always load the apps quickly
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It's how Android manages memory. It keeps your apps in memory until it needs to free some, at which point it starts to close apps to free some up. If they're already in memory they open fast because they're already open. If they aren't, they open more slowly.
There's not a ton you can do, really. Some 3rd party sms apps let you lock the app in memory, but I honestly never checked to see if it really works or not.
Personally, I restart my phone every morning when I wake up. This frees up the most memory and allows your phone to leave more apps open before closing them.

make sure you arent running any ****ty task killers.

You could flash an I9000 ROM/kernel that let's you tweak the lmk. (low memory killer)
Talon and semaphore both offer that option.
The trick is to make it weak enough to not kill the apps you want, but aggressive enough to not allow to run out of ram completely.
both of those kernels also have a "bigmem" version that gives the user a bit more ram at the cost of being able to record video in 720p.

studacris said:
You could flash an I9000 ROM/kernel that let's you tweak the lmk. (low memory killer)
Talon and semaphore both offer that option.
The trick is to make it weak enough to not kill the apps you want, but aggressive enough to not allow to run out of ram completely.
both of those kernels also have a "bigmem" version that gives the user a bit more ram at the cost of being able to record video in 720p.
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I like ur answrr. But can u pls guide me abt lmk. I like this idea but never use such tweaks. I m using talon kernel right now and rom is much fast. But have same prb of apps loading

In the app memory freak, that installed with the kernel, there is a slider for you to adjust,
lower number the more aggressive the lmk but the better the overall performance.
Higher number is less aggressive and is better for multitasking, but can be a bit slower.

studacris said:
In the app memory freak, that installed with the kernel, there is a slider for you to adjust,
lower number the more aggressive the lmk but the better the overall performance.
Higher number is less aggressive and is better for multitasking, but can be a bit slower.
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Where to find app memory freak ? i haven't seen any option in CWM

Should have been installed when you flashed talon. If not, it should be linked in the talon op.

[Q]Does Quasar kernel support swap?

hi guys,Does Quasar kernel support swap?and how to enable it?
i tried to enable it but failed
and i'm thinking about there's a lot of free space that i never used in /data and /system,so why don't we use those useless space to swap for more ram?
or we can use ZRAM?and how to use it?

we have 512 mb memory, for what you want swap?

actually the ram we can use only have less than 300mb

hmm partitionning SDC should do the job, isn't it ? do "ext" partitions have something to do with that ?

I think there's no reason to use swap, but dxdiag32's idea is not bad... internal memory is quicker than sd...
Regards.

Nah, it doesn't support it.
I did some tests with ZRAM and ZCache back in the LG P500 days and it didn't seem to help with anything so I usually disable Swap support now.
Anyway, you can always mount a tmpfs partition to some applications to boost their I/O operations if that's what you're looking for.
Huexxx said:
I think there's no reason to use swap, but dxdiag32's idea is not bad... internal memory is quicker than sd...
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Depends on the microSD card's class. A class 10 is faster than internal memory.
In fact, it's a shame they dropped the yaffs2 filesystem as in non-sequential I/O operations it's the best one.

Class10 is faster? At least internal memory will be less energy hungry... won't be?

Huexxx said:
Class10 is faster? At least internal memory will be less energy hungry... won't be?
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Yes, class 10 (>= 10 mb/s write speed) is faster than internal memory.
This is why moving app, data and dalvik to microSD when you have such microSD provides a good boost on I/O operations. There's many folks using the combo CM + S2E + MicroSD Class 10.
As for battery, it's a good question but I bet it should be the same. I/O stuff isn't heavy.

most of us now is using C4 sdcard,at least in China is .so i wanna give us some more performance.my free space in /data partition keep more than 800MB for a long time,and i think more ram can provide us more stable phone.

Beware that RAM works differently for Android devices.
Whereas free RAM in Windows is arguably better than occupied RAM, this is not so for Android. In Android, having RAM allocated is good which is also behind the reason of why we shouldn't use task killers. That being said, we don't really need more than 512 MB of RAM for a heapsize of 32 MB and proper OOM groupings and adj values! Even with an aggressive usage, it's unlikely you'll manage to trigger an OOM (out of memory) throughout your day.
Here's an oldie but goldie article regarding this:
http://lifehacker.com/5650894/andro...ed-what-they-do-and-why-you-shouldnt-use-them

ok got it , thanks knzo

knzo said:
we shouldn't use task killers.
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I understand the theory but because of my own experience I do not agree in 100% with You. My previous smartphone was Samsung Spica ( not much RAM ). I used to use my favourite IGO for navigation. It was impossible to succesfully launch IGO if I have not used task killer before.
Without task killer IGO just started and vanished within seconds.

pabgar said:
I understand the theory but because of my own experience I do not agree in 100% with You. My previous smartphone was Samsung Spica ( not much RAM ). I used to use my favourite IGO for navigation. It was impossible to succesfully launch IGO if I have not used task killer before.
Without task killer IGO just started and vanished within seconds.
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That's because IGO triggered an OOM event and the ROM you had instead of doing an intelligent swipe and killing applications based on certain heuristics, was killing the process responsible for the OOM instead (IGO). It's a flag in sysctl called: OOM kill allocating task.
So in that case, it was just a lousy ROM/kernel. Or perhaps in Spica (old kernel, old android version) there wasn't this setting and the phone always killed the application that made the phone run out of memory. This explains why it vanished after a bit.
Either way I stand correct, there's no need for task killers in a device with >= 256 MB of RAM or properly configured.

knzo said:
That's because IGO triggered an OOM event and the ROM you had instead of doing an intelligent swipe and killing applications based on certain heuristics, was killing the process responsible for the OOM instead (IGO). It's a flag in sysctl called: OOM kill allocating task.
So in that case, it was just a lousy ROM/kernel. Or perhaps in Spica (old kernel, old android version) there wasn't this setting and the phone always killed the application that made the phone run out of memory. This explains why it vanished after a bit.
Either way I stand correct, there's no need for task killers in a device with >= 256 MB of RAM or properly configured.
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Agreed. I still have my old Galaxy Apollo, with 256 MB ram it goes perfectly as it should. In fact, on a careful observation i 've noticed that if we use taskkiller at autokill level at let's say 30 minutes autokill, it will technicall consume 4 CPU cycles in an hour for each app (two for killing, and two when applications like gmail/facebook etc. starts automatically again).. but without taskkiller they may have stay idle, and not used any CPU cycle at all for as many hours as phone is idle. And for battery purpose, it is the CPU cycle that drain, not the used memory !

in my opinion,we only need to kill the apps that use internet in background to save battery.such as Google Maps,once i used it,its services stay in background and after 3 hours i didn't use phone do anything,battery drain 3%,and if i kill it,no battery drain after all

Google Maps and DRM service process sometimes cause battery drains indeed.

knzo said:
Google Maps and DRM service process sometimes cause battery drains indeed.
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i deleted DRM service,and seems it's no harm to system

Lol but do you know what is it function ?
Sent from my LG-P970 using xda premium

I've seen drm using a lot of CPU as well from time to time. What is it used for and how would you go about removing it?
dxdiag32 said:
i deleted DRM service,and seems it's no harm to system
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Sent from my LG-P970 using XDA App

masterthor said:
I've seen drm using a lot of CPU as well from time to time. What is it used for and how would you go about removing it?
Sent from my LG-P970 using XDA App
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You can use Titanium https://market.android.com/details?id=com.keramidas.TitaniumBackup
-Go to Backup/Restore tab
-Find by DRM Protected Content Storage
-Click and select Freeze
Now the app is Freeze and the system don't see more!

Speed up your Nook Color running ICS+

Hello all, today I will be showing you how to speed up your Nook Color a bit... these methods should work for CM9/CM10/CM10.1/Paranoid Android/etc., but I personally found these out while running PA ICS. The apps you may need to make your phone faster are Ram Manager (Free OR Pro) and No Frills CPU Control (In the case that your ROM doesn't have overclocking in settings). Basically, using these "tweaks" (minus overclock, as whenever I flash a ROM the first thing I do is overclock it), I went from a painfully slow (as in, I was ready to go back to Gingerbread) device to a somewhat faster device. I've seen huge differences in launching games and apps especially, and opening to app drawer seems to be smoother also.
CPU Overclock
Either using No Frills CPU Control or the built-in overclock, set your max CPU speed to the highest on the list (not exceeding 1200, but it shouldn't show anything above that anyhow). Change your governor to either Ondemand or Performance (I personally use Ondemand and have no problems with it). Most of you are probably already overclocked though, so please don't look at me like I'm stupid.
Swap Space
Open up RAM Manager and there should be an option to change your swap space at the bottom. I changed mine to about 48 and am content with that, although I must add it may make your SD card's life shorter. This will increase your RAM, thus allowing you to have more apps open at once.
Force GPU rendering
Open Developer Options in your settings app and check "Force GPU Rendering"... I'm guessing this is one of the biggest factors to my tablet becoming smoother, as from research it helps lower end devices achieve a better framerate, although it may decrease your battery life. Also, I cannot guarantee every app will run great with this. I tested a game (Dynamite Jack) with this setting enabled and it wasn't too shabby at all! But yes, I can definitely see a difference in the overall speed of my Nook Color.
Please tell me how these work for you

I tried these settings, but unfortunately didn't perceive any performance improvement.

Good call on RAM manager. Hadn't seen that before, its going on my NC and RAZR now

Can anyone tell me a good reason for that RAM Manager app to have the permissions it does? Location, Identity, and full network access?

Does NOT work. All this app " no frills CPU" does is provide a GUI front end for the settings already found for our nook color using CM 10+ in its "performace" settings. Also this app does not provide over clocking above our set 1100 MHz. You will need a custom over clocking kernel for the encore for this. Check over on the CM 10 kernel thread n the development section.

Memory management (keep maximum in ram)

All I would like to do is to keep apps maximum is possible in ram. My goal is for my daily use of most common apps like phone, whatsapp, google messenger, gmail, contacts, calendar etc. to keep them in ram so switching between them is smooth and fast without loading on anything. My memory is always more then 50% empty and little apps like calendar or contact are getting killed with no reason. That is really going on my nerves more and more.
I am on Pure Nexus CMTE rom and I have tried playing with Kernel Auditor low memory killer and virtual memory settings. What ever I do there my ram usage is always about 1 - 1.4 GB newer more then that. How I can force system to keep apps in ram until critical point? Like in my case with more then 50% of ram still available there should not be any apps removed from memory even if is app not active for some time. Can anyone please help me with this.

Possibly you see 1.5G free now, but it may have temporarily been a lot less free when the apps were killed (usage varies over time). See attached how high chrome can jump at its peak.
Just a thought..very half baked. I'm sure someone will give suggestions for what you want.

electricpete1 said:
Possibly you see 1.5G free now, but it may have temporarily been a lot less free when the apps were killed (usage varies over time). See attached how high chrome can jump at its peak.
Just a thought..very half baked. I'm sure someone will give suggestions for what you want.
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Yes, I know but Chrome memory usage is still nothing compare to free memory available. I did some reading and end up creating local.prop file in root/data and add some lines there. How much that will help I will find out in day or two. If anyone is interested to know what I did I can post it here after.

Just wanted to add that in Android N preview the low memory kill settings by default were very light (like lighter than kernel adiutor's "very light" preset) and it resulted in very stuttery performance. Setting them back to marshmallow stock settings made everything smoother. Looking forward to anything you may uncover on this though.

StykerB said:
Just wanted to add that in Android N preview the low memory kill settings by default were very light (like lighter than kernel adiutor's "very light" preset) and it resulted in very stuttery performance. Setting them back to marshmallow stock settings made everything smoother. Looking forward to anything you may uncover on this though.
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Okay this is what is confusing me the most. In Kernel Auditor "very light" preset means that apps will be removed soon is possible, very light means small amount of memory to be used. Am I correct? Aggressive on other hand will give more memory for apps, more apps in memory and less removing from it.
So if is that correct then is very understandable why "N" with less then "very light" preset made bad performance and soon you give it more memory to play everything is back to normal.
However I did test on that many times but in both cases my apps are getting removed from memory with more then 50% still available memory. That's why I need somehow to stop system from emptying memory until critical point. Maybe some build.prop lines can help but I am not really expert in that area.

Emilius said:
Okay this is what is confusing me the most. In Kernel Auditor "very light" preset means that apps will be removed soon is possible, very light means small amount of memory to be used. Am I correct? Aggressive on other hand will give more memory for apps, more apps in memory and less removing from it.
So if is that correct then is very understandable why "N" with less then "very light" preset made bad performance and soon you give it more memory to play everything is back to normal.
However I did test on that many times but in both cases my apps are getting removed from memory with more then 50% still available memory. That's why I need somehow to stop system from emptying memory until critical point. Maybe some build.prop lines can help but I am not really expert in that area.
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What is the solution for Pixel 2 rom of LG Nexus 5X? os ur build prop gonna help for me? if yes plz replay.

MHS3511 said:
What is the solution for Pixel 2 rom of LG Nexus 5X? os ur build prop gonna help for me? if yes plz replay.
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No idea man, I don't have LG Nexus 5 anymore. Today roms have that battery optimizations build in. Go there and make the app you like to be in memory "not optimized" and in Kernel auditor or any other app flashing memory to "very light". That should help. Good lack