Console related:
1. you need a PS3 with an OLD firmware (up to 3.55). Starting from 3.56, you can't install a custom Firmware anymore.
2. If your console is OLD but has an up to date firmware (4.xx), you can downgrade with a modchip but only up to the original firmware sold with the console. (if you bought a 3.56 console, you can't downgrade to 3.55).
3. You can't buy a new PS3 and downgrade it to fw3.55.
Custom firmware and dongle:
1. You need a custom firmware to launch unsigned homebrew (like Game Manager, media players, games, etc.)
2. Some Dongles (like Cobra or True Blue) require a Custom firmware too.
The dongle are only additional unlockable that simple custom Firmware can't provide. But dongle alone are not enough.
You need either :
- custom firmware 3.55 : Play old PS3 Games only.
- custom firmware 3.55 + dongle : Play old PS3 games, + specific options (cobra can play PS1/PS2) (True blue can play newer games)
Game related:
Custom firmware are running on firmware "3.55".
You can't run NEW games which require 3.60+ firmware (such as "naughty dogs game and the new game by who ever made quantum whatever.") unless you have a tru blue dongle + a patched game file.
Though, I'm personally against True blue dongle.
I don't recommend it.
but it's currently the only way to play newer games.
HDD related:
You can't play with a NTFS drive.
Only FAT32 is compatible with games.
NTFS is only usable to transfer game, but not to play from it.