Yesterday I received my EZ Flash Omega and followed the manual on the corresponding website. I read something about NOR flash. What are the advantages of using NOR flash?
The EZFlash cards contain two sets of memory: PSRAM and NOR. While NOR is persistent (i.e. it doesn't lose its content when the device is powered off), PSRAM is volatile.
On the older cards (EZFlash IV and Reform), loading a game into PSRAM would take 10-60 seconds, but the game gets unloaded from PSRAM once you power off the GBA - PSRAM was also limited to 128Mbit which covers the vast majority of GBA titles, but all the games with a size of 256Mbit could not be loaded into PSRAM.
Loading a game into NOR memory would take considerably longer (we're talking a few minutes here) but the game wouldn't be unloaded when powering the unit down. So when powering up the GBA later, you wouldn't need to load the game again, you would just be able to run it from NOR. Also, the NOR had a size of 256Mbit, allowing for the larger games (RPGs) to be loaded.
NOR was particularly usefull for games with a long playtime (RPGs for example) so you wouldn't have to load it into PSRAM everytime you wanted to continue.
The PSRAM in the Omega is as large as the GBA can address, so all games can be played from PSRAM. As far as I understand, the NOR on the Omega is only there because it's embeded in the PSRAM chip that they use, so it's "free" to use - not enabling it would just leave it unused on the device. With the PSRAM memory access on the Omega being magnitudes faster than on the IV/Reform, the Omega has basicaly instant boot times for loading games into PSRAM (we're talking about 2-3 seconds at max) and NOR memory has lost it's only advantage. NOR might still be faster, but even if it only takes 1 second to load from NOR, that time saving is basically negated by the minutes it takes to write the game to NOR in the first place.
Tl;dr:
NOR on the Omega is only there because it was trivial for the EZFlash team to implement it and it didn't have any influence on hardware or manufacturing costs, so they decided to keep it. It doesn't really serve any usefull purpose nowadays.
