SATA, eSATA, Power and Y Cable Assemblies
SATA cabling splits into two separate connectors that are usually discussed as one: a 7-position data connector and a 15-position power connector. They are specified independently, they fail independently, and a drive needs both.
Most of the trouble on this interface comes from treating them as a single line on a bill of materials. EPS builds both sides, and the conversions between them, to your specification.
On this page
- What connectors make up SATA cabling?
- Which power connector does your build actually need?
- What does a SATA Y cable actually split?
- What should you confirm before specifying a SATA or power assembly?
- What SATA and power assemblies does EPS build to specification?
- What information does EPS need to quote a SATA cable?
- Frequently asked questions
What connectors make up SATA cabling?
| Connector | Positions | Carries |
|---|---|---|
| SATA data | 7 | Data only |
| SATA power | 15 | Power only |
| Slimline SATA power | 6 | Power, slim-drive form factor |
| Molex peripheral power | 4 | Power, legacy supply side |
| Floppy power | 4 | Power, legacy peripheral |
| eSATA | 7 | Data, external shielded variant |
eSATA is the externally shielded variant of the SATA data interface, intended for connections that leave the chassis. It is mechanically distinct from internal SATA, and the two are not interchangeable.
Where a figure is shown as a dash, it is not published in the EPS catalog and is not asserted here. It is confirmed against your drawing or sample during engineering review.
Which power connector does your build actually need?
A drive states what it needs. The power supply states what it has. The cable reconciles the two, and that is where the specification actually lives.
A build may have to move between 15-position SATA power, 6-position slimline SATA power and 4-position peripheral connectors, in whichever direction the chassis requires. Adding a drive to a system whose supply has run out of the right connector is one of the most common reasons a custom power assembly gets specified at all.
What does a SATA Y cable actually split?
A Y cable takes one source and splits it to two destinations. On the power side this is routine, and it is usually about connector count rather than capacity.
Splitting power is a load question before it is a cable question. Two drives on one supply connector draw from one budget. The assembly does not create capacity, and a Y cable that is mechanically correct can still be electrically wrong for the system it is going into. Confirm the supply budget first, then specify the cable.
What should you confirm before specifying a SATA or power assembly?
- Which connector on each end, data and power separately. A drive needs both and they are specified independently.
- Internal or external. eSATA is a different mechanical interface, not a longer SATA cable.
- The routing path, not the straight-line distance. Length is measured around the obstructions, and it is the figure most often supplied wrong.
- Connector orientation. Straight, right angle, left angle, up or down. In a tight chassis this decides whether the assembly fits at all.
- For any Y cable, the supply budget. Splitting a connector does not split capacity.
- Latching or non-latching where the application involves vibration or service access.
What SATA and power assemblies does EPS build to specification?
SATA data assemblies, eSATA assemblies, SATA and slimline power assemblies, peripheral power conversions, and Y cable splits in either direction. You specify the connector on each end, the length, the orientation, the shielding and the termination, and the assembly is built to that.
EPS is a manufacturer rather than a shelf. Nothing here is a catalog number — it is a build defined by your requirement and confirmed in engineering review before quote.
What information does EPS need to quote a SATA cable?
- The connector on each end, with the family named and not only the position count
- Overall length, measured along the intended route
- Orientation and any clearance constraint
- Quantity, and whether this is a prototype or a production run
- Any environmental requirement — temperature, vibration, routing near heat
Frequently asked questions
What is the difference between SATA data and SATA power connectors?
They are two separate connectors. SATA data uses 7 positions and carries data only. SATA power uses 15 positions and carries power only. A drive requires both, and each is specified independently — which is why a working data cable and a missing power path is such a common cause of a drive that will not appear.
Is eSATA just SATA with a longer cable?
No. eSATA is the externally shielded variant of the interface, mechanically distinct from internal SATA and intended for connections that leave the chassis. The two connectors are not interchangeable.
Can I split one power connector to run two drives?
Mechanically yes, with a Y cable. Electrically it depends on the supply. Both drives then draw from a single budget, so confirm the supply can carry the combined load before specifying the assembly. A Y cable changes connector count, not capacity.
What is slimline SATA power?
A 6-position power connector used on slim-drive form factors. It is a different connector from the 15-position SATA power connector, and a build moving between the two needs the conversion specified explicitly.
Does EPS build SATA cables in custom lengths?
Yes. Length is a build input, measured along the intended routing path rather than straight line. Orientation, shielding and termination are specified the same way.
Looking for a stocked part rather than a custom build? See the SATA, power and adapter ranges at MicroSATACables.
Have a custom interconnect challenge that off-the-shelf parts won’t solve?
EPS engineers and manufactures precision cable assemblies, signal-conditioning AICs, and custom enclosures for OEM partners, in Acton, Massachusetts. Lead time is confirmed with your quote against the actual specification and volume.