THIS IS NOW AVAILABLE IN EXT2, EXT3, AND EXT4 VARIATES(DOES NOT REQUIRE CUSTOM KERNEL!)
IF YOU ARE USING JH2/JH3 FIRMWARE, READ THIS POST, IT IS VERY VERY VERY IMPORTANT:
The reason this step is important is that the JH2 firmware is a test build, and as a test build it has GPS logging enabled... this uses an absolutely ludicrous amount of storage space- and the real kicker? It uses the space OUTSIDE of this fix, meaning your phone will encounter low space warnings very quickly if not instantly upon applying the fix!
THIS NOTE IS FOR EVERYONE. THESE FIXES WORK BETTER FROM A FRESH FLASH. THEY *CAN* WORK WITHOUT A CLEAN FLASH BUT REALIZE THAT YOU ARE POTENTIALLY PUTTING YOUR DATA AT RISK!
What this does (Shamelessly stolen from RyanAZ's OP)
Creates a VIRTUAL EXT2 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.
Doesn't rely on external SD
Easy to do
Real, noticeable performance increases outside of Quadrant (Seriously don't pay attention to Quadrant, but if that's what you care about this will make your pants tighter)
Uses EXT2 file system which is non-journaled and CAN become corrupted, frequent backups are strongly recommended! (2.2 Implements error checking every 30 mounts)
It's also up for debate as to whether this adds extra strain on your internal memory.
1.0 SECTION WILL FOLLOW 2.0 STUFF
AS WITH ANY FIX: READ THE INFO, KNOW WHAT YOU'RE DOING, AND UNDERSTAND POTENTIAL CONSEQUENCES!
LINKS TO GET THE GOODS BELOW!!
The RyanZA version that does EXT2 is Available at the thread linked below
RyanZA has put out an APK version of the fix for people less comfortable doing the update.zip or batch file methods! (This is the V1 lagfix, so for people having issues with the newer fixes this one might work for you!)
TEMPORARILY DOWN UNTIL VERSION 2.3
There is also an update.zip version that does EXT2, EXT3 (1500 Quadrant), or EXT4 (1800 quadrant) versions thanks to Tayutama! I've tested this to work on JH2, and JM5 firmwares! There is also a special version for Captivate JH2 (It also works for JH3) that fixes the GPS Log issues so no need to edit the XML's yourself!
praveer01 threw up a handy writeup for those of you running Unbuntu or any other Linux system:
READ THE INSTRUCTIONS AND REMEMBER THIS IS *VERY* BETA, NEITHER RYANZA OR MYSELF WILL TAKE RESPONSIBILITY FOR MELTING YOUR DEVICES OR KILLING YOUR DOG IF THIS FAILS. That said, this thread has been very good about helping people who borked their Captivates with 1.0
Here's the reasons you'd want to do this:
Benefits over version 1
1.7GB of application data available, with no data loss. (Up from < 1GB)
e2fsck of the EXT2 partition on each boot. (To scan and fix corruption!)
Correct busybox version included! YES! (Because no one can get it right =P)
/app directory included in the fix for faster application installs.
Mounts instead of symlinks for extra performance as OS does less work (about 100 or so more quadrant).
/dbdata has been removed. This fixes maps issues.
/app-private is now a symlink to /app/app-private. This fixes paid apps issues.
/app-private is included
A second EXT2 partition is created in fast /dbdata storage. /dbdata/databases are moved inside here for increased speed in applications that use it. (System apps mostly, I think)
Proper parameters for e2fsck.
0% space reserved in the EXT2.
EXT2 partition reduced from 1.7GB to 1.5GB to allow more space for captivate users.
Running from a stock install of JH2 I'm currently getting 2300 quadrant scores with ALL AT&T BLOATWARE AND TW ENABLED!
IF YOU'RE NEW TO THIS KIND OF THING, OR ARE WORRIED ABOUT POSSIBLY HAVING TO REFLASH YOUR PHONE, YOU PROBABLY SHOULD WAIT A LITTLE WHILE FOR MORE PEOPLE TO TEST THIS!
Found this over in the i9000 forums and tested it myself- I'm getting 2100+ quadrants scores with the stock Captivate kernel and it doesn't hang up on the I/O portion like all the other fixes... in addition you don't require an SDcard for this to work.
One of the folks over there created a one-click lagfixer and it DOES work for the Captivate:
FOR PEOPLE WHO DONT WANT TO READ THE ORIGINAL THREAD
This fix creates a 1GB file formatted in EXT2 and moves all of your apps, data, dbdata into it which DRASTICALLY improves I/O performance. One advisory SHUT YOUR PHONE DOWN PROPERLY, this means no yanking the battery out. Due to it being EXT2, non graceful shutdowns CAN cause corruption.
Edit: No wake up lag either- not sure if that's due to using a non-modded kernel or because the ext2 file is located on the internal memory.
Edit 2: Make *SURE* before attempting this that you have Busybox 1.17.1 or the boot animation script calls won't work!
Link to Busybox 1.17.1
DO NOT UPGRADE BUSYBOX TO 1.18! 1.18 REMOVES MAKEFS WHICH IS NECESSARY FOR THIS PROCESS
Edit 3: I haven't used the stock Captivate ROM for a while, but this feels quite fast- Also worth noting that this SHOULD work with any ROM- including i9000, I might test that later but I'm enjoying having functioning haptic feedback. 2200 Quadrant with Shootme and market running! Since seeing is believing I've thrown in a screen cap.
Confirmed working with JM5 ROM
IF YOU USE A MAC OR JUST CAN'T GET ADB TO WORK THIS FIX CAN BE PERFORMED WITHOUT A PC- SEE THE POST BELOW: