Enhanced Integrated Drive Electronics (EIDE) is an improved version of the traditional IDE storage interface standard. It offers enhanced features and follows the ATA-1 specification, using a specialized cable to connect hard drives to the motherboard. EIDE supports data transfer rates ranging from 4 MB/s to 16.6 MB/s.
Understanding EIDE
EIDE is an extension of the original Integrated Drive Electronics (IDE) interface, designed for connecting mass storage devices with higher data transfer rates. Developed by Western Digital, EIDE is commonly used in IBM-compatible computer systems and is known by several names:
- Advanced Technology Attachment (ATA 2)
- Fast ATA
- Fast IDE
- Parallel ATA (PATA)
These terms are often used interchangeably, as they all conform to the ATA-2 standard. EIDE can also be referred to as ATA-3, which offers additional features like SMART support and uses a 44-pin connector.
EIDE serves as a communication interface between mass storage devices and computer systems. Its parallel data transfer allows for higher speeds compared to its predecessor.
Key Features of EIDE
- Faster data transfer rates (up to 16.6 MB/s in Mode 4)
- Support for Ultra ATA (ATA-3) with transfer rates up to 33 MB/s
- Larger hard drive capacity support (beyond 528 MB)
- DMA and PIO support
- ATAPI functionality
Despite its advantages, EIDE has been largely replaced by faster interfaces in modern computers.
Characteristics of EIDE
EIDE offers several improvements over its predecessor:
- Support for multiple data transfer modes (PIO modes 3 and 4, DMA modes 1 and 2, Ultra DMA)
- Ability to connect up to four devices on the secondary port
- Logical Block Addressing (LBA) support for hard drives larger than 500 MB
- Compatibility with CD-ROM, DVD-ROM, and Tape Drive devices
- Lower cost compared to SCSI drives of similar capacity
However, EIDE drives generally offer lower performance than SCSI drives due to:
- Smaller cache sizes
- Lower spinning rates
- Higher seek times
EIDE Cable Connections
The EIDE cable primarily connects to the hard disk drive. It can also connect other devices such as:
- CD-ROM and DVD-ROM drives
- Zip drives
- Tape backup drives
- Other ATA peripherals
EIDE Drive Support
EIDE can support up to four devices:
- Two primary devices
- Two secondary devices
This limitation is due to the design of EIDE/IDE controllers and cables, which allow two devices to be connected to each cable.
Conclusion
EIDE was a significant improvement over the original IDE standard, offering higher data transfer rates and support for larger hard drive capacities. While it was well-suited for low-cost computer systems with a couple of hard disks and a CD-ROM drive, EIDE has since been superseded by faster interfaces like Serial ATA (SATA) in modern computers.