what is swap space?

[DROIDpfft]

i have clockwork mod and i formatted my card for apps2sd and it asked for a swap space partition. i searched for it on here but no one explains what swap space is? i overlooked something about ram, and im thinkin it's the amount of space you allow your phone to store apps on and not the sd??
im confused ha

[LtKen]

Swap space is effectively virtual RAM, it's significantly slower than actual RAM, but it gives the processor a place to move data that needs to remain in memory, but it doesnt have room for.

Paging - Wikipedia, the free encyclopedia

[aaf709]

Let me google that for you

[DROIDpfft]

Let me google that for you

how come when i typed that in google it didnt give me that helpful link? ha thank you everyone! so now your phone has the internal ram AND virtual External?

[ohioDroid]

Let me google that for you

how come when i typed that in google it didnt give me that helpful link? ha thank you everyone! so now your phone has the internal ram AND virtual External?

Computers use both internal and virtual RAM. Internal is faster, but is usually smaller and more expensive, so data used less often is placed in virtual RAM. Another reason can be that you're using so much RAM and don't have enough physical internal RAM, so the computer/phone stores it virtually to your virtual space, in this case an SD card.

[Se7enLC]

Let me google that for you

how come when i typed that in google it didnt give me that helpful link? ha thank you everyone! so now your phone has the internal ram AND virtual External?

Yes, but keep in mind that the external virtual ram will be slower than the internal ram, and swapping programs in and out of it will create lag. Android OS already handles low memory conditions by forcing apps to save state and quit, restarting again when requested. For most apps, it would look exactly the same to you.

Additional swap space on the SD card is only going to be a benefit if you run a LOT of apps that NEED to stay running in the background. If you're just using email, browser, IM, etc, you're not going to gain anything, and you will probably even LOSE some performance, as it won't kill off things that it should.

I believe cyanogenmod has an option for turning swap on and off. I recommend turning it on for a few days, turning it off for a few days and seeing what sort of difference you notice in different situations (single program running, multiple programs running, etc). See which one feels faster to you.

As a comparison point - on a normal linux system, there's a term called "swap death", which is what happens when you run out of memory and things need to get swapped to disk (virtual memory aka swap partition). Everything running slows down to a point where the system is almost entirely unresponsive and may even only be recoverable with a reboot. If the system runs COMPLETELY out of memory, it will start killing tasks without much warning or recourse. On the other hand, because Android OS and Android apps are designed to be killed off and restarted transparently, the low memory is a non-issue, since it is already swapping things in and out for you, even without swap space.

[aminaked]

lmgtfy.com is so good