[Captivate Android Development] Zilch25:
HOW THIS WORKS (Stolen from RyanZA)

Creates a VIRTUAL EXT2 or 4 filesystem inside the stock RFS filesystem on the internal SD card, with a 4KB block size. This means that this lag fix creates a buffer between the real filesystem and the android system. This buffer should reduce the amount of disk I/O required for all operations by utilizing EXT2 buffering, as well as not writing file access times to disk, etc.

Since the inception of this concept there have been a few different versions of the Lagfix, I'll describe them a bit below:

Tayutama's Update.zip method (recommended)

http://xdaforums.com/showthread.php?t=765820

- Tested extensively, this new version actually does all of the file movement while the phone is still booting so the chances of your data and apps disappearing, or corrupting is massively diminished. This Lagfix can be applied in both EXT2 and EXT4 flavors and both perform amazingly! This fix also corrects the Captivate gps logging problem! Make sure you install the "with root" version if you aren't rooted, and the "without root" version if you are or the fix may fail! DO NOT INSTALL USING ROM MANAGER!

Is EXT2 for me?

If you want your Quadrant scores to be bloated beyond belief and don't care if your data spontaneously combusts (Results may vary). Alternatively if you're worried about your NAND wear leveling not being able to handle the strain of EXT4 journaling.

Okay EXT2 is scary, how about EXT4?

You can't afford for your things to get corrupted? Weirdo. Real world performance between EXT4 and EXT2 is barely noticeable if at all, for the everyman this is probably your best bet.

The RyanZA Oneclick Lag Fix APK

http://xdaforums.com/showthread.php?t=760571

This fix is marketed to people who aren't comfortable with scripting! It's not designed to compete directly with the other lag fixes out there, but if you're a self proclaimed "noob" this is probably the route for you!

The RyanZA Oneclick Lag Fix V2-3

http://xdaforums.com/showthread.php?t=751864

This is the lag fix that a lot of you will be coming from if you have one already (Exceptions would be SRE users) and the origin of most of the lag fixes used currently. This lag fix is mostly the same as Tayutama's new version with three exceptions: A) EXT2 is the only supported file system B) EXT data file is created and data is moved while the OS is running so it's a tad riskier C) It moves the data from /data/app into the virtual FS.

GENERAL THINGS YOU SHOULD KNOW

PEOPLE WHO ARE USING JH2 OR JH3 AND A MARKET FIX THAT SPOOFS YOUR BUILD.PROP TO JF6 SHOULD MANUALLY DISABLE GPS LOGGING!! IF YOU DO NOT YOUR PHONE WILL FILL UP WITH LOGS AND DISABLE APP INSTALLS/SMS

http://xdaforums.com/showpost.php?p=7650658&postcount=312

As with anything on XDA there's a chance things you do here could harm your device, whether or not creating a file system within RFS will cause your hardware to die prematurely is up for debate, it's suggested that you educate yourself on what you're doing to your hardware before you do it!

Most fixes of any kind will perform best from a clean odin flash, though the most recent release of Tayutama's fixed is targeted at the audience who has a ton of apps installed it comes with NO GUARANTEES, myself and other users have spent a good amount of time testing out different revisions of these scripts to decrease the likelihood of cataclysmic data loss, but your mileage may vary.

If you have any questions or anything feel free to post in this thread, we'll do our best to help you along!

Credits:

Thanks to ykk_five for being brave enough to goof with the file system enough to figure out the loop trick in the first place!

Thanks to RyanZA for coming up with the initial fix that stuck past reboot and his continual development for the SGS

Thanks to Tayutama for his tireless dedication to making sure this fix works as best it can, even with all the Captivate specific curveballs :D

Many thanks as well to the people besides myself who have been brave enough to load these experimental builds onto their phones (A moment of silence for all the apps who lost their lives in the pursuit of a snappier SGS)