Database Develop

[Q] RAM

Can anybody explain to me something about how the RAM works? So the phone has 512 mb of RAM, and only 330 available (I guess the OS takes the rest to 330). From those 330, around 100 are always used by something hidden. What is that?
Also if I stop some of the running services, sometimes that memory remains used.
What does eat my memory over time? I mean after some hours following a reboot my memory slowly starts to become used.
In the Running services tab there is a list of cached services and if I close any of them it eats more memory. How does that work?
I know, these questions are annoying.

128mb for tegra. that's why you have only 300mb+ for available memory

But why if I stop some processes such as the music player the RAM doesn't clear?
And why if I stop something from the Cached Processes tab it eats my RAM? (I can't find out what those cached processes are actually)

as far as i understand the system keeps it in memory in case you open something again and then it doesnt have to load everything over. and if there isnt enough for new apps it clears some ram.
this is not windows and the ram is supposed to be full. if im wrong about that someone correct me...
Sent from my Optimus 2X using XDA App

Yes you're right but the way Android kills processes when needed can be optimized, as sometimes the system is slow to free ram. In fact there are threshold values for different situations, that say to the system to free ram.
So the solution is not a standard task killer, but an optimization of values that triggers memory clean up. It's done for example by scripts like the one I use, see in my signature.

[Q] Galaxy Note RAM capacity

Note Specs say 1GB RAM. My unit shows 385MB used by applications and 100 MB available. Is the rest used by the System?? How to check if my unit has really 1GB RAM installed???

Note has 1gb Ram, 200mb. reserved for GPU
Enviado desde mi GT-N7000 usando Tapatalk

Galaxy Note RAM capacity
OK, buT 200MB plus 385 MB used + 100MB available still do not make 1 GB!

Note have 792 available on OS, some it is user by android stock apps and services.
When I boot the phone with about 30 services and 400 apps installed I always have free about 380mb, so look the permissions to see what apps are autostarting with the boot and change them.

Galaxy Note RAM capacity
"When I boot the phone with about 30 services and 400 apps installed I always have free about 380mb, so look the permissions to see what apps are autostarting with the boot and change them."
Please tell me how to "look permissions" and change apps at boot???

Moved To Q&A​
Please post all questions in the Q&A section​

I hope you'll find answer to your questions. By the way, I'd like people to understand that free ram is UNUSED/USELESS. Our target as users and/or developers is to achieve the "enough ram for every process and app" objective. That is, we absolutely want that every bit of ram is used to make the whole system faster and readier. If you have services you need ready to be executed in ram, and you have ram for all of them, you have the best resources / results ratio. If you have 1GB of free ram and every app you need must be raised from scratch, you're not using your resources the optimal way. My 2c - maybe ot?
Good luck with your findings, anyway.
Sent from my Milestone using XDA App

Galaxy Note RAM capacity
Thanks for your message. However, I read in many forum messages that too many apps in the RAM slow down the display reaction, which I found myself too.
However, I've just done the 10-second soft reset and found my RAM usage went down to 187MB used and 530MB available for services. Also found in applications management RAM capacity info: 372MB used out of 800MB. I suppose difference comes from the fact that the first capacity info relates to the space available for applications and the second used capacity includes applications AND System.
But in this case it means the Note has 800MB and not 1GB of RAM as advertised!

It has 1GB as stated. 200 MB are used by the OS. 800+200=1000.
Sent from my superior GT-N7000 using Tapatalk

Galaxy Note RAM capacity
Thanks for the message.
But why the active applications list on the bottom says 187MB used and 530MB available RAM , while the task manager/RAM management shows 372 MB used space out of 800MB??
This is what confuses me: in one place it is shown that 178MB is used and in another 372 MB used !???
Please clarify !

Radivoj said:
Thanks for the message.
But why the active applications list on the bottom says 187MB used and 530MB available RAM , while the task manager/RAM management shows 372 MB used space out of 800MB??
This is what confuses me: in one place it is shown that 178MB is used and in another 372 MB used !???
Please clarify !
Click to expand...
Click to collapse
depends o nthe kernel you are using, but the note has 1gb of ram of whcih 800 is available for the system to use

Radivoj said:
why the active applications list on the bottom says 187MB used and 530MB available RAM , while the task manager/RAM management shows 372 MB used space out of 800MB??
This is what confuses me: in one place it is shown that 178MB is used and in another 372 MB used !???
Please clarify !
Click to expand...
Click to collapse
The difference is because the active applications list in running services does not include the amount of RAM used to cache apps. You can press option key while in running services, there should be an option called "show cached processes".
If you add the amount of RAM used for both cached and running apps in running services, the total should be similar as the amount of RAM used in Samsung task manager.
This is because Android considers cached apps as free memory. They are background processes that are not visible or directly affect our use of the device and can be killed to free up memory to run service processes (i.e. user launched apps).
The cached processes basically are a list of recently used apps stores in reverse order, i.e. the least recently used app is at top of the list and most recently used app is at the bottom of the list. This way if the phone is running out of memory, it will start to kill off app at top of the list, so the app that was last used will be the last one to be killed.
The idea of cached processes is to improve the start-up time of an app the next time the user needs to run it.
P.S. I'm not an expert in Android operating system, this is just my general understanding of how Android RAM management processes.

Thank you very, very much for clarification. Now everything becomes clear and consistent !
Best regards,
Radi

marmotash said:
Note has 1gb Ram, 200mb. reserved for GPU
Enviado desde mi GT-N7000 usando Tapatalk
Click to expand...
Click to collapse
When I check running applications tab insettings, I can see total RAM as 800 MB. Thanks for clarifying. I had the same doubt. But is there any way to check how much RAM is allocated to GPU using any android setting? I am keen to know this.
Many Thanks,
Nikhil Bhalwankar

[Q] Now, what is it with the free ram?

So here I am running Infinitum (AOKP) v2.1 with Devil2 0.72, 402 MB edition.
So this is the amount of free ram I have:
~20 MB. *click*
NO WAIT! its 150 MB! *click*
errr... no... its still just ~20 MB *click*
So why would android tell me I got 150 MB of free ram and 'free' command tells me something quiet different? I really don't get it, hope some1 can enlighten me :/
Thanks!

Many apps are cached/pre-buffered like in Windows, so in reality RAM is used more. This 150MB physically is not free, but it's available for apps that needs RAM - memory from this 150MB will be 'cleared' instantly.

So I am not running critically low on memory?
But I guess more ram would anyway benefit the overall performance since android could cache/pre-buffer even more, right?

You can check Memory usage with the SystemPanel app: it will list all active applications / system processes and services / cached applications , showes what amout of ram they're using and can kill the unnecesserary apps on the spot with it!

[Q]most great set for SDCard

Just simply question guys,but I confuse about this
*swap enable/using swap partition
*using ext partition over moving apps2SD normally
Is this could be better than normal/standard SDCard?
I have Transcend 16GB Class 10 using fat32+ext4 (using link2sd)
But I felt not different with my VGen Class4 8GB
Please guys if you have experience about this,,tell whats wrong n what were I missed for
Thanks
Sent from my Spice Mi-410 using Tapatalk 2

Arya_3RDNumber said:
Just simply question guys,but I confuse about this
*swap enable/using swap partition
*using ext partition over moving apps2SD normally
Is this could be better than normal/standard SDCard?
I have Transcend 16GB Class 10 using fat32+ext4 (using link2sd)
But I felt not different with my VGen Class4 8GB
Please guys if you have experience about this,,tell whats wrong n what were I missed for
Thanks
Sent from my Spice Mi-410 using Tapatalk 2
Click to expand...
Click to collapse
I'll try to answer base from what I know....
"*swap enable/using swap partition"
About this, we have to know what is swap, swap type and do we need it?
swap is the another partition which will be used as an extra memory. As we know, memory is been accessed VERY OFTEN in a process, both read and write.
On linux PC commonly we use one partition on disk drive for linux swap. On windows it's using a file as a virtual memory.
Swap is needed when the application need large memory to be used for a process and the current ram is not enough. Well there are some priority list to be followed. Ok, I'll give an example if we run a big game in an android. we have ~350MB total user memory but let say we have 50MB free memory. Most of android BIG 3D games will not exceed 300MB of memory, the game designer will look to target phone which will run it, and they presume all user don't have swap memory. But let say the app will need about 300MB of memory to run.
1. If we have 50 MB swap partition in sdcard
Android will never deplete the real ram, so let say it will keep 10MB of free ram, it will be use for the android system rom to keep running. In this situation the app will take 40MB of free ram, 50MB of swap... and what about another 210MB? Android will take it from the real ram by kill another apps (based on priority of low memory killer setting) to reallocate the ram. So for the game, the real ram will be taken about 250MB and 50MB from swap and free ram about 10MB. another 90MB of real ram used by the system and another hidden app like framework setting, messaging and others and for app cache. About 250MB ram used by game app is accessed very fast, but 50MB of swap if very slow because of access speed of sdcard is very much slower then ram.
When exiting from the game, some hidden apps still in memory. Android will run one or two another residen apps.
2. If we have 50 MB swap zram
Zram is swap partition in real ram, not sdcard. Any data written to the zram is compressed and decompressed on the fly. For 50MB zram, let say we can get about 80MB swap because of compression. the ratio depend on data been compressed.
Just like said in point 1, android will keep 10MB of free ram for the android system rom to keep running. The app will take 40MB of free ram, 80MB of swap. The real ram is 350MB - 50MB(zram) = 300MB, 290MB will be available for apps. The app will take 80MB from zram, and use 220MB from real ram. So 290 - 220 = 70MB of ram will used by android system and for app cache.
About speed of game between those 2 swap type, zram will be faster for sure because it use ram rather then sdcard. And one thing I feel necessary to let you know. Not as in PC which using HDD as storage which almost has unlimited write cycle. But we use SDCARD which has very limited write cycle. So consider using swap partition in your sdcard, even if it has very fast write/read speed. It will significantly affect your sdcard life.
When exited from the game, few hidden app still reside in memory. Android will run few another residen apps.
3. If we not use any swap
The game will take 300MB of ram, and let 40MB of ram used by android system. More apps have to be killed by android low memory killer system.
When exited from the game, only one or two hidden app still reside in memory. Android will run some more another residen apps.
It's your decision to use swap or not. The need is depend on your behave of use of this phone and the types of apps installed, such as more widgets, tools and some residen apps. Try every option, and you will get the result. The result could be different with another user, depend on behave and the apps installed.
*using ext partition over moving apps2SD normally
If you really have your internal storage depleted, let say you have installed hundreds of apps, then yes you will need app2SD or ext partition on sdcard.
The read and write speed of internal storage and sdcard will definitely win by internal storage (You have class 10 of sdcard? just test the write speed of internal storage).
ext partition is access directly while app2SD using 3rd app, so using ext partition should be faster then app2SD.
Just 1.5 cents....
Do you understand what I've talked about???? Well.... I don't!!!

I'm a noob and it cracks my skull. Great explanation though:good:

wow??!! great explanation agan master
well I understand very much after read 1000times
Thanks a lot gan,,I must little experiment to realize
Now I understand what is "ZRAM" (sorry I really noobie )
about all this case,,is ZIPALIGN also complicate?

Well... actually my explanation hasn't completed yet. I was mentioned about priority, I didn't explained it. It about low memory killer configuration and also the priority of using swap. You can Google that .
About zipalign, it related with apk files. It intended to make it faster to load. Apk file is a compressed file. But I don't have any further knowledge regarding this. May be someone can explain it.
Sent from my bike using Tapatalk 2

Ram being used

Wondering what is taking so much ram up when no applications are running is it just TouchWiz? Anyway to free up ram on stock?

I noticed the same thing however when I go to settings then application manager and see the apps that are running I noticed that it shows that I have 1gb of ram free ?

Something is up with your phone because mine only uses 1.3gb of ram with no apps running, with a bunch of apps it's like 2.3gb-2.5gb

Mine is the same as the OP...not sure what gives

Free RAM is wasted RAM.