So, the above, combined with Backgrounder and SBSettings make a WONDERFUL combination. with VM enabled, if you use SBSettings to free up ram, what it will do is use up all memory except 64MB and that forces everything else to swap. This leaves a 3GS or ipad with about 180-195MB of free memory :) … and if you use that you.. you can free it again.

Also, your memory should NEVER drop below 60-64MB with the above VM steps I posted above. When the system gets near 64MB, you will notice a little bit of lag (I have SBS display free memory at the top of the screen). The lag last only a few seconds as the dynamic pager swaps more data to storage. This is a handy thing as your device will never run out of memory.

I DO NOT recommend this for ANY device with 128MB of RAM!!! I tested this on an iphone 3G, and the performance was TERRIBLE! This is because those devices have so little ram, turning on the pager will make it CONSTANTLY grind the files. This WILL drain battery VERY VERY fast.

Pluse a lot of the .plist files you get on the internet do not work. THEY MUST BE A PLIST FILE IN PLAIN TEXT TO WORK!

com.apple.dynamic_pager.plist goes into: /System/Library/LaunchDaemons

A SECOND file is needed to make sure the swap files are NOT encrypted. If you do not add this file. Your device can be slow, sluggish and crash… a LOT:

com.apple.virtualMemory.plist goes into: /private/var/preferences

Here are the contents of what each file should be. Just make a plain text file and SSH them to the above mentioned places:

com.apple.dynamic_pager.plist
—————————–

< ?xml version="1.0" encoding="UTF-8"?>
< !DOCTYPE plist PUBLIC “-//Apple//DTD PLIST 1.0//EN” “http://www.apple.com/DTDs/PropertyList-1.0.dtd”>
< plist version=”1.0? >
< dict >
< key >KeepAlive< /key >
< true />
< key >Label< /key >
< string >com.apple.dynamic_pager < /string >
< key >ProgramArguments< /key >
< array >
< string >/sbin/dynamic_pager< /string >
< /array >
< key >RunAtLoad< /key >
< true />
< /dict >
< /plist >


com.apple.virtualMemory.plist
——————————

< ?xml version=”1.0? encoding=”UTF-8?? >
< !DOCTYPE plist PUBLIC “-//Apple//DTD PLIST 1.0//EN”
“http://www.apple.com/DTDs/PropertyList-1.0.dtd” >
< plist version=”1.0? >
< dict >
< key > UseEncryptedSwap < /key >
< false/>
< /dict >
< /plist >


UseEncryptedSwap

With the above, and using backgrounder. I’ve had enough apps running to have 1GB of swap space. I read in another post someplace that someone had said the idevice pager won’t simulate ram, WRONG. It does. iOS is just a scaled down version of OS X. It fully uses the swap files as ANY OS would.

The above way will make an initial 64MB swap file. Then it will make additional 64-128 (and sometimes 256MB) files. When your device is rebooted, the dynamic pager daemon auto deletes them for you ;)

keywords: iphone, ipad, ipod, swap file, virtual memory, dynamic pager