Related
Can anyone direct me to a guide somewhere?
I'd like to make an ext partition? Or would I? Is Swapper 2 just as fast? Tradoffs? Anyone run into their sd card wearing out yet?
bueler?
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The consensus seem to be "do not use" except as 'last resort', and only needed on phones with 256MB or less of mem.
I wrote this, and I am waiting for a technical review from some experts in this field.
http://forum.xda-developers.com/showthread.php?t=897823
kschang said:
The consensus seem to be "do not use" except as 'last resort', and only needed on phones with 256MB or less of mem.
I wrote this, and I am waiting for a technical review from some experts in this field.
http://forum.xda-developers.com/showthread.php?t=897823
Click to expand...
Click to collapse
I have 256MB ram
At the moment, Compcache is good enough, but I can't help but wonder how much better it could be with swap instead of Compcache.
edit: "For example, If you have a 256MB system (shows as 262MB due to 1024 vs. 1000 KB size difference) and have 130MB of apps and data/cache loaded, then that leaves about 130MB for the system to actually RUN programs. That sounds like a lot, but in reality that is not enough, since the system itself takes 50-80MB, and services will take up another 30-50MB, leaving almost nothing. "
quick review, you don't appear to be differentiating between RAM and Flash? Having more apps installed shouldn't increase RAM usage at all. Unless I gravely misunderstand the Android OS, if I install a new program, it resides in the system flash, not the RAM, until I run it, at which point it gets loaded to RAM. When the system needs memory and no swap or Compcache is in use, it writes the state of the application to the flash and removes it from RAM.
What the swap does is similar to what compcache does-- compresses apps that are currently in RAM, and moves them to the swap space. In the case of Compcache, this is in the RAM. But since you're compressing it, background apps don't take nearly as much RAM, and you get an app switching speedboost because the processor can uncompress the compcache'd program, "move" it to RAM, compress the currently running program in RAM, and "move" it to the compcache. Forgive me if you already said this, I can't read the entire thing at the moment.
As for swap, I'm not sure if the processor compresses before going to the hard swap file, I don't think that it does-- when android starts getting low on RAM, it moves what was in RAM, to the swap on the SD-card. Since it does this when the system is low on RAM, and not when the system runs out of RAM, you never notice it. Reading the app back from the SD card happens almost instantaneously, because the sd cards can be read from at a speed of at least 20MB/s, maybe more. When you're restoring an app to RAM, 20MB/s is plenty.
edit2: I'm sorry but this guide is too vague to be anything more than moderately informative. Comments like:
-"CompCache, or "compressed cache", is handled by the Linux kernel. It takes a portion of your memory, and use it as a cache space, but compressed. By using on-the-fly compression it is able to make your memory appear to be a bit larger than it actually is. However, the result is slower performance.
This is usually NOT tweakble without mod ROM such as Cyanogen Mod. The kernel also must support this feature, and not all do. This also slows your phone. "
-"...swap space by either creating a swap file or a swap partition. This adds a lot of read/write action to your SD card and may substantially decrease its usable life."
-"This really slows your phone."
People wouldn't be doing these things for no reason. Compcache does not "make your memory appear a bit larger", when it at least doubles the amount of usable RAM-- when you allocate 60MB, if you average 75% compression (I usually see between 65% and 80%), do you know how much RAM this effectively nets you? Over at least 60MB extra, usually about 80! So my phone goes from having 256MB ram to having 340 effectively. Having your processor overclocked minimizes any slowdown from the compression/decompression; I haven't noticed any slowdown, and having the "extra" RAM definitely has made my phone more able to multitask.
You basically discourage users from doing ANYTHING like swapping, compcaching, etc to their phone, saying it "slows it down" and "can substantially decrease your SD Card's life". My experience has been otherwise regarding slowing it down, and regarding the SD card, the only part that would actually go bad is the swap partition. If you put that at the end of the drive, when it goes bad, you'll know, and you can just move the partition back 300MB and put your 300MB swap there. We haven't heard of any users' cards going bad from this yet. Also, if you have a class 6+ SD Card, they implement wear leveling on the card, so you don't need to worry about wearing out any individual bits.
Sorry, I'm just not digging it.
rancur3p1c said:
I have 256MB ram
Click to expand...
Click to collapse
Me too, me too...
At the moment, Compcache is good enough, but I can't help but wonder how much better it could be with swap instead of Compcache.
Click to expand...
Click to collapse
So try it. With CM612, I have CompCache AND Swap (through Swapper2 / 128 MB) turned on. It slows down every once in a while but my programs don't crash any more.
edit: "For example, If you have a 256MB system (shows as 262MB due to 1024 vs. 1000 KB size difference) and have 130MB of apps and data/cache loaded, then that leaves about 130MB for the system to actually RUN programs. That sounds like a lot, but in reality that is not enough, since the system itself takes 50-80MB, and services will take up another 30-50MB, leaving almost nothing. "
quick review, you don't appear to be differentiating between RAM and Flash? Having more apps installed shouldn't increase RAM usage at all. Unless I gravely misunderstand the Android OS, if I install a new program, it resides in the system flash, not the RAM, until I run it, at which point it gets loaded to RAM. When the system needs memory and no swap or Compcache is in use, it writes the state of the application to the flash and removes it from RAM.
Click to expand...
Click to collapse
At first I thought the same way you did, until I started looking in "diskusage".
According to diskusage, there is no separate RAM. 256MB is 256MB. App storage is where everything goes, and what's left is used to load services and such. The numbers I added up matches. I have 256 MB phone. 100 is for apps, which leaves about 150-160. System itself takes 50-80 (acore, gapps, phone, system...) then add a few services and you're down to 30-40 MB free to actually run the programs. The numbers seem to match up to what's shown at the bottom of "Manage Services".
I know it's weird, but perusal of Android developers kit doesn't contradict this understanding.
What the swap does is similar to what compcache does-- compresses apps that are currently in RAM, and moves them to the swap space. In the case of Compcache, this is in the RAM. But since you're compressing it, background apps don't take nearly as much RAM, and you get an app switching speedboost because the processor can uncompress the compcache'd program, "move" it to RAM, compress the currently running program in RAM, and "move" it to the compcache. Forgive me if you already said this, I can't read the entire thing at the moment.
As for swap, I'm not sure if the processor compresses before going to the hard swap file, I don't think that it does-- when android starts getting low on RAM, it moves what was in RAM, to the swap on the SD-card. Since it does this when the system is low on RAM, and not when the system runs out of RAM, you never notice it. Reading the app back from the SD card happens almost instantaneously, because the sd cards can be read from at a speed of at least 20MB/s, maybe more. When you're restoring an app to RAM, 20MB/s is plenty.
edit2: I'm sorry but this guide is too vague to be anything more than moderately informative. Comments like:
-"CompCache, or "compressed cache", is handled by the Linux kernel. It takes a portion of your memory, and use it as a cache space, but compressed. By using on-the-fly compression it is able to make your memory appear to be a bit larger than it actually is. However, the result is slower performance.
This is usually NOT tweakble without mod ROM such as Cyanogen Mod. The kernel also must support this feature, and not all do. This also slows your phone. "
-"...swap space by either creating a swap file or a swap partition. This adds a lot of read/write action to your SD card and may substantially decrease its usable life."
-"This really slows your phone."
People wouldn't be doing these things for no reason. Compcache does not "make your memory appear a bit larger", when it at least doubles the amount of usable RAM-- when you allocate 60MB, if you average 75% compression (I usually see between 65% and 80%), do you know how much RAM this effectively nets you? Over at least 60MB extra, usually about 80! So my phone goes from having 256MB ram to having 340 effectively. Having your processor overclocked minimizes any slowdown from the compression/decompression; I haven't noticed any slowdown, and having the "extra" RAM definitely has made my phone more able to multitask.
Click to expand...
Click to collapse
It also seriously depends on your SD card. I've read reports on Phandroid that said class 6 or 8 microSD cards would provide almost lag-free swaps, but that's on a G1 (which is already a slow phone).
You basically discourage users from doing ANYTHING like swapping, compcaching, etc to their phone, saying it "slows it down" and "can substantially decrease your SD Card's life". My experience has been otherwise regarding slowing it down, and regarding the SD card, the only part that would actually go bad is the swap partition. If you put that at the end of the drive, when it goes bad, you'll know, and you can just move the partition back 300MB and put your 300MB swap there. We haven't heard of any users' cards going bad from this yet. Also, if you have a class 6+ SD Card, they implement wear leveling on the card, so you don't need to worry about wearing out any individual bits.
Sorry, I'm just not digging it.
Click to expand...
Click to collapse
Constantly reading and writing the file will cause that area to get much heavier use and eventually cause it to fail the bootup "checking SD card". The only question is how much life is taken away.
I am running my Droid on 24% CompCache AND 128MB Swap right now. Occasional lag but otherwise runs quite well. It's also overclocked to 1.2 GHz with P3Droid's kernel. So I do practice somewhat of what I preach...
so if I have 512MB of ROM, and 256MB of RAM, and I fill up my ROM with programs, how much RAM do I have?
I don't follow how what you said can be.
SD Card writes-- SanDisk guarantees theirs for 100K writes to any given sector...that's good enough for the swap to not be a problem in the near future IMHO.
let's put it this way...
Here's the specs of Moto Droid from Motorola itself (http://developer.motorola.com/products/droid/)
RAM 256 MB
FLASH ROM 512 MB
USER STORAGE AVAILABLE (MAX) 256 MB
So the REST of the ROM clearly is to hold the Android OS itself. The actual programs you can load for running? 256MB. That's app storage.
I've always wondered if there's a way to read the actual ROM contents and enumerate that... But that's for another topic.
Found this useful post: boot process of Android OS
http://www.androidenea.com/2009/06/android-boot-process-from-power-on.html
Furthermore, I noticed that the "built-in" apps (i.e. bloatware) are actually just stuff left in the "system" dir which can only be accessed with root permission. So they are NOT store in "ROM" per se, but more like "part of boot rom".
I have to find explanation on how an app is loaded, but that helps...
Aha, so that's the term they used... Application Lifecycle.
http://www.youtube.com/watch?v=ITfRuRkf2TM
Okay, I take back what I said. Apps are loaded into RAM, but HOW things are allocated wasn't that clear.
From what I understand, apps, when they are killed by system, some exit gracefully by writing their instance "state" (data and cache) to app storage. Some just exits.
Browser will write the URL, for example. When the browser is "resumed", the process is loaded, then the instance loads back the URL and it's as if nothing happened.
I'll have to revise the paper, AND I haven't figured out what to say about swap and compcache yet.
Made some corrections.
On 256MB machine, 30MB is used by deep system buffers (not part of OS), another 32 for OS cache, so about 190 or so is available the OS itself to load apps and services, and just the default gapps, system, phone, and so on is about 60MB. So a fresh clean phone should ahve no more than 120-130 MB free. If you load a couple apps with autostart services, it'll quickly drop below 50MB.
http://stackoverflow.com/questions/2298208/how-to-discover-memory-usage-of-my-application-in-android
Another piece of the puzzle... The numbers at the bottom of "Manage Services" is as explained below:
(quoting from http://android-developers.blogspot.com/2010/02/service-api-changes-starting-with.html )
"Finally, along the bottom of the screen are some obscure numbers. If you know how to interpret them, this gives you a lot of information on the memory status of your device:
* Avail: 38MB+114MB in 25 says that the device has 38MB of completely free (or likely used for unrequired caches) memory, and has another 114MB of available memory in 25 background processes it can kill at any time.
* Other: 32MB in 3 says that the device has 32MB of unavailable memory in 3 unkillable processes (that is, processes that are currently considered to be foreground and must be kept running)"
The order is reversed in Android OS 2.2. Mine says
Other: 75MB in 5 Avail: 18MB + 20 MB in 3
Which should mean 75MB in 5 unterminable tasks, 18 MB free (or can be freed easily), plus another 20 MB used by 3 processes that can be killed to free up.
ProCrank says...
39911K System_server
15756K acore
12982K swiftkey
10136K DIY Screensaver (lock screen)
9392K Phone (system)
9093K ATKfroyo
6834K Terminal
3984K JuiceDefender
3785K Screebl
3482K system MMS
3329 SeePU
3244K Bluetooth
3199K SetCPU
1979K Zygote (which is Dalvik init)
1425K Mediaserver
and the rest is native system code well under 1MB in size.
If you add System_server, Phone, Zygote, Acore, and foreground app (terminal and procrank) you get about 75MB. It would be nice if that screen TELLS you which program it considers to be unterminable, but, oh well...
I'm new here at xda, I hope somebody can help me with some questions and ideas that I have about android and other devices Ram in general.
SOOooo. I've heard that the iPad and various iDevices use a special ram technique where only the current running application is loaded into the RAM. when an application is closed, what the application had in the RAM is written to memory or to sd card, when the application is resumed, it is written back into ram.
Whether this is true or not I am not sure, but I am certain that this type of memory swapping would increase ram efficiency.
For android (I'm not certain how windows phone works) an application could be made that instead of sending the close command when a back or home button is pressed, the application could be frozen and have its RAM written to the sdcard. On resume the data could be loaded back into ram and unfrozen.
Please could anyone inform me if such an app exists, or explain why it wouldn't work.
I had a search about and really I am only looking for confirmation as to whether this is accurate or not...
CALIBAN666 said:
I think its better to Post this here,when its not better,than sorry!!!
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Once a brief statement for those who are not traveling so long in the Android scene:
ZRAM = ramzswap = Compcache
In order to explain more precisely ZRAM first need other terms are more clearly defined:
Swap can be compared with the swap file on Windows. If the memory (RAM) to complete the PC the data that are being used not actively outsource (eg background applications) so as to re-evacuate RAM free. To this data is written to a hard disk. If required, this data is then read back from there easily. Even the fastest SSD is slower than the RAM. On Android, there is no swap!
In ZRAM unnecessary storage resources are compressed and then moved to a reserved area in the fixed RAM (ZRAM). So a kind of swap in memory.
This Ram is more free because the data then only about 1/4 of the former storage requirements have. However, the CPU has to work in more because they compress the data has (or unpack again when they are needed). The advantage clearly lies in the speed. Since the swap partition in RAM is much faster than this is a swap partition on a hard drive.
In itself a great thing. But Android does not have a swap partition, and therefore brings Android ZRAM under no performance gain as would be the case with a normal PC.
In normal PC would look like this:
Swap = swap file (on disk) -> Slow
ZRAM (swap in RAM) -> Faster than swap
RAM -> Quick
With Android, there is no swap partition, and therefore brings ZRAM also no performance boost.
The only thing that brings ZRAM is "more" RAM. Compressed by the "enlarged" so to speak of the available memory. That's on devices with little RAM (<256MB) also pretty useful. The S2 has 1GB but the rich, and more than. There must not be artificially pushed up to 1.5 GB.
After you activate the ZRAM also has 2 disadvantages. The encoding and decoding using CPU time, which in turn has higher power consumption.
Roughly one can say (For devices with more than 512MB RAM):
Without ZRAM: + CPU Performance | + Battery | RAM
With ZRAM: CPU Performance |-Battery | + RAM
For devices with too little RAM so it makes perfect sense. But who shoots the S2 already be fully complete RAM and then still need more?
Check whether you can ZRAM runs in the terminal with
free or cat / proc / meminfo
I hope it helps to understand zRam!!!!
Click to expand...
Click to collapse
Taken from here
That looks accurate, but it's a little hard to understand. A basic explanantion of zRAM is that zRAM compresses an actual block of RAM in order to have more RAM available to the system. If you make the compression too high with zRAM then your device will actually go slower as a result. An example of going over the top would be adding 256MB of RAM using zRAM on a phone that only has 768MB RAM (that's almost a 50% compression rate because ~600MB is available to the user). zRAM also requires the CPU to compress and decompress the data.
Zram is not ram. It is a virtual memory, also known as swap space, which lives in the ram. Virtual memory is the part where the system stores memory fragments which are not accessed, making more room for apps to store information in the ram. Most Pcs work with virtual memory on disk, but Linux has a zram feature, aka CompCache, which can hold unused pages in a compressed manner in memory, thus makes more ram available by compressing unaccessed pages.
Sent from my HTC Sensation Z710e using xda premium
so this ZRAM tweak is only useful for devices with low RAM's isn't it? well thanks for the info i dont wanna sacrifice batt life for some unnoticeable effect on my s3
once zram is enabled ....how do u remove the partition completely from.the ram after disabling it?
I noticed that my galaxy s duos comes with zram . However I wish to disable the partition and instead use swap partition in /cache .
So....how do I completely remove the partition space in ram?
Thank you .
Virtual Memory
Raven2k said:
Zram is not ram. It is a virtual memory, also known as swap space, which lives in the ram. Virtual memory is the part where the system stores memory fragments which are not accessed, making more room for apps to store information in the ram. Most Pcs work with virtual memory on disk, but Linux has a zram feature, aka CompCache, which can hold unused pages in a compressed manner in memory, thus makes more ram available by compressing unaccessed pages.
Sent from my HTC Sensation Z710e using xda premium
Click to expand...
Click to collapse
Sorry but you have a wrong concept of "Virtual Memory".
Google "virtual memory wiki" for the full article.
All programs have access only to their own "virtual" memory space of 4GB on 32bit OS'
But internally to the OS, that full virtual address space is divided on pages of 4KB each.
The OS manages all programs pages, if not enought RAM is available, it starts writing pages to the Page File / Swap partition.
When a program tries to read or write from its virtual memory address which page is not on physical memory, the OS launches a Page Fault Exception, takes over execution and reads the faulty page from storage (page file or swap partition) to physical memory, and if necessary writes another page to storage to make room for the requested page. Then it resumes the program execution.
From the article. Android does not have a Swap partition, but it compresses pages to ZRAM.
geno83 said:
Sorry but you have a wrong concept of "Virtual Memory".
Google "virtual memory wiki" for the full article.
All programs have access only to their own "virtual" memory space of 4GB on 32bit OS'
But internally to the OS, that full virtual address space is divided on pages of 4KB each.
The OS manages all programs pages, if not enought RAM is available, it starts writing pages to the Page File / Swap partition.
When a program tries to read or write from its virtual memory address which page is not on physical memory, the OS launches a Page Fault Exception, takes over execution and reads the faulty page from storage (page file or swap partition) to physical memory, and if necessary writes another page to storage to make room for the requested page. Then it resumes the program execution.
From the article. Android does not have a Swap partition, but it compresses pages to ZRAM.
Click to expand...
Click to collapse
True but not completely.
Android doesn't require ZRAM nor swap to work. It is a linux fraction but it doesn't act like linux completely.
Could anybody tell me the best way to improve ram efficiency without sacrificing batt
Thread cleaned. Either post relevant replies or don't post.
Right now, I have a full ZRAM. How does RAM handles it?
Sent from my Moto G4 Plus using XDA Labs
This may be a general question for all android devices or not but I was curious about adding swap space to this device. It has 1 gig of ram and many may consider that to be enough, and it might be. I have cyanogenmod 10.2 installed and tried to enable zram, 10% seems to be the best setting as anthing higher caused a game to pop up a notice saying something about low memory and defaulting to lower values. When I checked to see if zram was used however it turns out it was, about 25mb - 34mb after booting. The issue with zram is when multitasking with lecturenotes and moonreader, The tablet would reboot and my notebook that was open in lecturenotes would be missing notes I took or the settings would be greatly messed up, or both. This was with 10%.
I am thinking since it was used, it might be helpful to have an sd card for this reason, to aid in multitasking. This is important to me because I run several apps at once (I wish cyanogenmod had multi windows, and google wouldn't threaten over it). So the question is will there be a benifit to buying an sd card on ebay (class 10 of course) and using it as swap space. It seems this tablet might be on the cusp of the memory being enough. Also I am thinking this might help to future proof it a bit when updating to newer releases of gyanogenmod. The sd card I was thinking of is 4 gigs and may plan on having 1gb swap space (this tablet is for school and other work). The tablet has 32gb storage and that is more than enough for me (I am only using 3gb of space) so I wont need to add anymore storage.
I should also add that when multitasking without zram enabled, the tablet reboots less but still has done it, and so far nothing has been lost in my notebooks. I am thinking that the memory of 1gb is starting to reach its limit, with no apps running I am consuming about 600mbs of it.
vanquishedangel said:
This may be a general question for all android devices or not but I was curious about adding swap space to this device. It has 1 gig of ram and many may consider that to be enough, and it might be. I have cyanogenmod 10.2 installed and tried to enable zram, 10% seems to be the best setting as anthing higher caused a game to pop up a notice saying something about low memory and defaulting to lower values. When I checked to see if zram was used however it turns out it was, about 25mb - 34mb after booting. The issue with zram is when multitasking with lecturenotes and moonreader, The tablet would reboot and my notebook that was open in lecturenotes would be missing notes I took or the settings would be greatly messed up, or both. This was with 10%.
I am thinking since it was used, it might be helpful to have an sd card for this reason, to aid in multitasking. This is important to me because I run several apps at once (I wish cyanogenmod had multi windows, and google wouldn't threaten over it). So the question is will there be a benifit to buying an sd card on ebay (class 10 of course) and using it as swap space. It seems this tablet might be on the cusp of the memory being enough. Also I am thinking this might help to future proof it a bit when updating to newer releases of gyanogenmod. The sd card I was thinking of is 4 gigs and may plan on having 1gb swap space (this tablet is for school and other work). The tablet has 32gb storage and that is more than enough for me (I am only using 3gb of space) so I wont need to add anymore storage.
I should also add that when multitasking without zram enabled, the tablet reboots less but still has done it, and so far nothing has been lost in my notebooks. I am thinking that the memory of 1gb is starting to reach its limit, with no apps running I am consuming about 600mbs of it.
Click to expand...
Click to collapse
Well in my own personal testing i could not see any benefit while extracting 700mb archives under android with 4gb swap space on a 40mbs microsd card, while under full linux desktop with a same workload, swap differently helps keep the system smooth under heavy io load. The conclusion i drew was the android platform deals to memory management differently than the typical desktop os, due to slower emmc chips used as a boot disk for the majority of android devices using this slow, already bottlenecked memory as swap space doesn't make sense (not to mention the use of 2gb swap space on a limited 16gb storage etc), so android runs almost completely in ram, with stricter memory management and allocation allows android to run fine without swap space, although because of this, androids memory management makes little uses of available swap space
JoinTheRealms said:
Well in my own personal testing i could not see any benefit while extracting 700mb archives under android with 4gb swap space on a 40mbs microsd card, while under full linux desktop with a same workload, swap differently helps keep the system smooth under heavy io load.
Click to expand...
Click to collapse
I've been running my desktop without swap for the last 10 years, and as long as you have enough RAM for all your running programs, there will be no problem at all.
Extracting an archive is a mostly sequential operation (single read stream, single write stream), so it also doesn't benefit from caching, which could use the memory that is freed by swapping.
_that said:
I've been running my desktop without swap for the last 10 years, and as long as you have enough RAM for all your running programs, there will be no problem at all.
Extracting an archive is a mostly sequential operation (single read stream, single write stream), so it also doesn't benefit from caching, which could use the memory that is freed by swapping.
Click to expand...
Click to collapse
Ahh that makes sense. I wasnt sure if swap had an effect directly on the extraction, but seem keeped the rest system more stable/ smooth duing the process in the case of GNU/Linux, with swap off similar operations such as installing packages would more oftern lock the tablet up. Might be a placebo though
I also dont set swap on my Linux desktop, as it has plenty of ram but the benitfit of swap space is somewhat more noticable due to the lack of ram on the tf700.
JoinTheRealms said:
I also dont set swap on my Linux desktop, as it has plenty of ram but the benitfit of swap space is somewhat more noticable due to the lack of ram on the tf700.
Click to expand...
Click to collapse
I just want to share my user experiences on the swap space... It does seem to improve the tf700 with swap space due to the lack of RAM (1GB)..
Thanks for all the useful posts
Thanks for all the posts, I have my sd card on the way. I will post my experience when I get my sd card but I am sure it is safe to say there will be a benefit. I use linux to at home and have 8 gigs of ram on that computer, I lessen the swap after install to about 512mb because 8 gigs is more then enough. I leave some however just incase of any issues like ram going bad. On another computer in the house that has limited ram (1.5 gigs) I have enabled zram (384 mb) and added two old flash cards (1 gig each) to a pci raid card and those were converted to swap. I then altered the fstab to reflect the order of priority I wanted them used in. The reason is that when the swap is used from the hard drive, and the hard drive is being written to, can cause a slow down. So with the 2 flash cards at 1 gig each (the swap seen as 2 gigs) it seemed to speed it up. I just posted that because of the nix users and it seemed like a good plan to run it that way.
Ok, got the sd card
So I recieved the sd card today and applied the swap space to it using root swapper (max setting is 256mb, I figured i can find a way to increase it later if I need to). The defaut location in many of the swap applications will not work on this device however, the sd card mounts at /storage/sdcard1 in my case. So it has to be entered manually (might just be cyanogenmod). Also the device was picky when insalling the card, it would only say blank sd card or cannot read filesystem. I had to install the card in the dock, format it from cwm recovery, (vfat if I remember correct, ext2 and ntfs had issues, avoided ext3 and ext4 cause journaling will cause more wear and tear).
The sd card is a scandisk ultra sdhc uhs-1 8 gigs. From my research that is the fastest this tab can handle. I also use optimising programs like greenify (epic save everything app), pimp my rom (almost every tweak applied), and some pretty efficient tweaks in the settings as well. I also have HALO))) installed and working (epic multiwindow app that works with native programs and almost any rom).
The resuts:
I tested it many ways, I rebooted to see use (none was used because swap starts after boot), I opened apps normally (browsers and things), and it showed 9kb's was used. I then put it to the tests, I open four windows in halo, these were youtube, moonreader pro with a pdf ebook, lecturenotes (awsome note and handwriting app with tons of functions), and Supernote pro (not the best note app). Constantly switched between the apps and messed with settings with them open. The max of swap used was around 10mb(keeping in mind that when I switch windows the app(s) I leave get paused making it hard to tell actual usage because I had to swith the terminal and type "free". I then ran antutu bechmark and gpubench (my tab stills score pretty well) and got a little higher swap usage but not much.
As for the feel of it, it seemed to help when opening many windows in halo, this is the primary reason for my doing this. As for other more normal uses I really didnt see too much of a difference, I did test games however and they did seem a little better (could be placebo) but I am not really sure why they would except android cached other apps to free memory. Reopening apps seemed faster. Also because of apps like greenify my memory usage is decreased so I am sure typically swap would have seen more use.
The conclusion is that at this point I really didn't notice much of a boost for any normal use, but I will definately keep the swap space on due to the boost when using halo and not to mention that I will be updating to android 4.4 soon and it might need more memory. Swap at this point seems more like a pre emptive strike, but it does help with multitasking.
about swap
://androidforums.com/boost-mobile-warp-all-things-root/610449-ram-swapping-without-swapper2.html I actually followed a guide on android central and redid the swap file to 1 gig to swap instead of using a program, this worked better. (add http in front), when i disabled swap it was noticeable that there was a boost. then reenabled it this method.
Hello everyone,
I need some help with expanding RAM of an old android tablet of mine, more specifically, an Genesis GT-7204, using an SD card.
I rooted the tablet already and granted the app RAM Expander from Roehsoft root permissions, but when i try to use the app i get the following message: "This path is not available for swap!" Image below:
https://imgur.com/4MZ2l
The path i used was mnt/local:
https://imgur.com/6zUH7
Thanks in advance!
The images might be blocked, in any case i will post them here.
Personally have experienced that Virtual RAM ( aka SWAP RAM ) can only get created on a device's internal storage memory ( aka /sdcard ).
Hint: As path manually enter /data .
BTW:
Android since ever comes with virtual RAM ( SWAP RAM) feature. The internal storage memory used herefore is the /cache partition.
Also take note that an Android apps' memory usage by design is limited to some MBs. Even if you increase in Android's system file called build.prop the related amount, it's not sure that this is taken into account: an app's develeoper allows this or not.
And keep in mind that apps that did not fit in the RAM before without swap do not suddenly fit in the RAM.
Don't expect wonders using Roehsoft's RAM Expander. Probably you may not notice any gain in device's performance.
So i can only use my internal storage to add RAM? And not the SD card?
And to do this i have to manually set a path, but i am new at this, but i have to use /data or there is something else?
And in my case it is worth it, because this freaking tablet has only 500 MB of RAM!!!!!
jwoegerbauer said:
Personally have experienced that Virtual RAM ( aka SWAP RAM ) can only get created on a device's internal storage memory ( aka /sdcard ).
Hint: As path manually enter /data .
BTW:
Android since ever comes with virtual RAM ( SWAP RAM) feature. The internal storage memory used herefore is the /cache partition.
Also take note that an Android apps' memory usage by design is limited to some MBs. Even if you increase in Android's system file called build.prop the related amount, it's not sure that this is taken into account: an app's develeoper allows this or not.
And keep in mind that apps that did not fit in the RAM before without swap do not suddenly fit in the RAM.
Don't expect wonders using Roehsoft's RAM Expander. Probably you may not notice any gain in device's performance.
Click to expand...
Click to collapse
So i can only use my internal storage to add RAM? And not the SD card?
And to do this i have to manually set a path, but i am new at this, but i have to use /data or there is something else?
And in my case it is worth it, because this freaking tablet has only 500 MB of RAM!!!!!
pprg1101 said:
So i can only use my internal storage to add RAM? And not the SD card?
And to do this i have to manually set a path, but i am new at this, but i have to use /data or there is something else?
And in my case it is worth it, because this freaking tablet has only 500 MB of RAM!!!!!
Click to expand...
Click to collapse
Honestly I never used Roehesoft's RAM Expander on a real Android device and I'll never will use it: In my eyes it's crap. And, you'll find no serious confirmations in the WEB that it works as claimed.
Android for good reason doesn't come with SWAP feature. Android's Memory Manager frees RAM if necessary.
It's on you to play around with Roehesoft's RAM Expander. Good luck.
My last 2 cents here:
SWAP is a place on the internal storage memory (usually a dedicated partition) that is used to store programs or data that can't fit in memory, like when a program grows more than the available RAM (BTW: In the world of Windows this space is called Swapfile.sys ). SWAP is way slower than RAM, so when you create / enable SWAP the phone gets slower, but at least the program can work.
All the stuff that can't or shouldn't stay in your RAM is written out to SWAP and read back in when needed. This means that the SWAP medium needs to be fast and resilient to lots of writes.
IMHO using an external SD card as SWAP fails on both counts. It is slower at reading/writing than a phone's internal drive, and each of its constituent sectors can only be written to a limited number of times before they wear out and can no longer reliably store data.
SC pl