which one is better sd or ide

[aykiri1]

(16.12.2016 18:17)megavolt85 писал(а):  

(16.12.2016 17:15)aykiri1 писал(а):  iso loader settings what i must select ? emulation ,memory adress,IP.BIN, etc...

Dreamcast GDI Compatibility List

(16.12.2016 17:15)aykiri1 писал(а):  neogeo emulator not working (but cd version is working)

neo4all

(16.12.2016 17:15)aykiri1 писал(а):  which extention is better one (iso,gdi or cdi) and must convert to each other ?

optimized gdi

thx @megavolt85
sd or hdd which one is better for games ? hdd faster than sd but any other important difference option between them ?