PATA (IDE) vs SATA

IDE Ribbon Cable  vs   SATA Cable

*** also see the SATA FAQ  and SATA-IO

The maximum internal data rate on an IDE disc drive today has peaked, and is about 133MB/sec. Due to the crosstalk that develops when wirws are placed side-by-side as they are in every parallel cable . . . that data path in PATA has reached its limit. Serial ATA allows disc drives to continue the march onward to grater speeds.

SATA II already greatly exceeds the sustainable (non-burst)
transfer-rate of even the best hard-disks !!

 

YEAR Transfer Mode Standard Transfer Rate
in MBps (MegaBytes/sec) for ATA
in Gbps (GigaBits/sec) for SATA
1997  Ultra DMA 3 / ATA-33 33.33
1999  Ultra DMA 4 / ATA-66 66.6
2000  Ultra DMA 5 / ATA-100 100
2001  Ultra DMA 6 / ATA-133 133

2002

 SATA I
- aka SATA/150

 1.5 Gbps
(192 MBps)

2003

  SATA II *
  - aka SATA 3 (due to the data rate), SATA/3.0 or SATA/300)		 3.0 Gbps
(384 MBps)

Future

  SATA III 6.0 Gbps

* the organization that created the SATA standards hates the name, SATA II - because that was their own name of their organization !!  They have been trying to wipe out use of that name but it has not worked - it is stuck and embedded now.  The organization then changed their name to "Serial ATA International Organization, or SATA-IO"

PATA - Parallel ATA - Parallel Advanced Technology Attachment - uses the IDE interface and cable - has been the hard disc drive interface for desktop PCs for over 15 years. Parallel ATA can be found in desktop PCs, Notebook, Consumer Electronics, and in some servers today. A new interface, Serial ATA, is replacing Parallel ATA technology.

SATA - Serial ATA - Serial Advanced Technology Attachment - uses the SATA interface and cable - leverages the Parallel protocol and enhances it by serially moving data across a thinner more flexible cable. PATA hard drives, however, still exist in great numbers within the market. Until the complete transition from Parallel to Serial occurs many, many PCs will continue to ship and use Parallel ATA hard drives.

eSATA (external SATA)

Standardized in mid-2004, eSATA defined separate cables, connectors, and revised electrical requirements for external applications:
  • Minimum and maximum transmit voltage increased to 500 mV - 600 mV (from 400 mV - 600 mV)
  • Minimum and maximum receive voltage decreased to 240 mV - 600 mV (from 325 mV - 600 mV)
  • Identical protocol and logical signaling (link/transport-layer and above), allowing native SATA devices to be deployed in external enclosures with minimal modification
  • Maximum cable length less than 2 metres (USB and Firewire allow longer distances)