[EVO 4G General] Tical79:
Ok, I must really be either bored or like you, because this is my second time writing this...

For those that are more technical, forgive my oversimplification, and feel free to chime in and correct as necessary...

:)

It may help you to think of your phone's (application related) memory as 3 types:

Internal – this is the smallish amount of flash memory built into the phone, it's precious and seems to go quickly if you aren't careful. :mad:

“SD Card” – this is the memory you are able to see when you connect the phone to your computer, it's cheap, expandable but usually slower and quirky (from an app standpoint), it's also where apps go when you use the 'move to SD' function

SD Ext3 – This is a small partition on the card that you made if you followed the directions of the first post. It comes at the expense of SD Card space, but it's worth it...

On a 'normal'/stock install, most apps will try to install themselves into your internal memory. This is good in the fact that the internal memory has great read/write speed and bad that you don’t really have a lot of it. Google addressed this in android 2.2 (froyo) by allowing apps to be installed/moved to the sd card. You can do this yourself by menu>settings>applications>manage applications. Select one, and odds are, it says, 'move to SD card'. This would let you move most of it's data to a special folder on the SD card, saving precious internal memory. The downside is that it's a pain to do one at a time... That's where all those apps in the market apps2sd, apps 2sd pro, blah blah blah, come in. They make it easy to move lots of apps back and forth to being installed on the sd card and/or internal memory. Technically, it's nothing you can't do by hand, but they make it nice and pretty. Another downside to this method is that not all apps can get moved, and some that do act funny when they are (widget related apps especially act wonky)...

So to address this issue (and the lack of ability to do so pre-froyo), some people much smarter than you and me figured something out ;). They worked it so you could make a small partition on the pysical SD card that acted more like internal memory. So you install apps as if it's internal, but it's really on your physical card. It's the best of both worlds, the lack of headaches associated with internal memory, but the large size from the card. But, in order to make it work, a script is run to make android treat part of the sd card as if it's internal memory. One of the more popular is the CM a2sd script. It's built into lots of ROMS, including Synergy. When you install the rom, it checks to see if you have this partition on your SD card, and if so, it automagically lets the script to do it's thing. That's what you made in the beginning... a small ext3 partition that effectively expands your internal memory when used in conjunction with the script. They work together, useless in and of themselves. But one of the great things about android is evolution...

So, in addition to apps, one of the other things that (normally) resides on your internal memory is the davlik cache. Google the specifics, but this is what helps your apps run, and run well. The possible downside of using the ext3 partition and a2sd script is that this cache ends up on your physical sd card. Assuming you have the stock card, read/write is going to be slower on that, than the true internal memory. So, some other folks, again, much smarter than you and me, came up with a variant of the script (DT a2sd) that allows you to force the cache back onto the true internal memory. So even though there is less 'true' internal memory, the cache is in the fastest place, so it's a performance tradeoff. The DT a2sd does some other things, but this is the relevant point here. There is even an app on the market that lets you turn some of the features of the script on/off , including forcing the cache location. Since the CM a2sd and the DT a2sd do pretty much the same thing, running both at the same time is problematic, hence the warnings...

If you want to see the whole thing in action, install a ROM that includes the script and open Titanium Backup, on it's first page at the bottom, it breaks down the memory types for you and how much they are used. You'll see that as you add apps, they will reside on the ext3 (called SD a2sd in TB). Ultimately, you are going to have to make the search button your best friend, and put a few hours or so into educating yourself, but hopefully, this gives you a basic framework to go with. Once you become knowledgeable, be sure to pass it on to someone else who may have a question or two.:D

Hope this helps, and I reserve the right to be completely wrong about everything stated here and will happily accept corrections. :p