Most of the time, the 4 bit mode is used because almost every IDE now comes with a 4bit LCD interfacing library. So no one likes to use 8 bit mode to loose 4 precious IO pins!
A four bit bus is also a lot slower to get the data to the screen, than the 8 bit version. But is does save quite a few pins. For most of my projects pins are more important than speed.
A four bit bus is also a lot slower to get the data to the screen, than the 8 bit version. But is does save quite a few pins. For most of my projects pins are more important than speed.
The speed difference is only minimal, and not significant - LCD's are slow devices, and this swamps the tiny speed difference between 4 and 8 bit modes.