4000 SX (250-4900) IDE Connectors Faxback Doc. # 1530 Integrated Drive Electronics (IDE) let you install up to two hard drives without having to buy and install a hard drive controller adapter. Although the IDE system requires IDE-type hard drives, an IDE drive can function the same as a standard ST-506 type hard drive. If you choose not to use the IDE system and to install a different type of hard drive system, such as ESDI or ST-506, you will need to change a dip switch setting on the main logic board so that the new hard drive controller adapter can take over.