Quick Answer
Most external hard drives do not have SATA ports. External hard drives typically connect to computers via USB, Firewire, Thunderbolt or other data cables and do not require SATA ports. However, some external hard drive enclosures, especially those designed for larger 3.5″ hard drives, may include a SATA port to connect the internal hard drive to the enclosure’s bridge board or interface. So in certain cases, an external hard drive can have an internal SATA port, but it is not externally accessible and is solely used to connect the hard drive inside the enclosure.
What is a SATA port?
SATA stands for Serial Advanced Technology Attachment. SATA is an interface used to connect storage devices like hard drives and solid state drives to a computer’s motherboard.
SATA ports and cables provide a serial connection that supports high speed data transfer rates. The most common type of SATA port found on desktop and laptop computers is SATA III, which offers transfer speeds up to 6 Gb/s.
| SATA Version | Max Transfer Speed |
|---|---|
| SATA I | 1.5 Gb/s |
| SATA II | 3 Gb/s |
| SATA III | 6 Gb/s |
Physically, a SATA port on a computer or motherboard looks similar to the image below:
The distinctive L-shaped SATA port accepts a SATA data cable on one end, while the other end of the cable plugs into the hard drive or SSD. Some SATA ports may also support an additional power connection if the drive requires extra power.
So in summary, SATA ports provide a fast serial connection from a computer’s motherboard to internal storage drives like hard disks and SSDs. But what about external hard drives?
Do External Hard Drives Have SATA Ports?
In most cases, external hard drives do not have SATA ports. This is because external hard drives are designed to connect to computers differently than internal drives.
There are a few key differences between external hard drives and internal hard drives:
- External hard drives are housed in an enclosure which protects the drive and provides connectivity. Internal drives mount directly to the computer.
- External drives connect to computers via external cables and interfaces like USB, Firewire, eSATA or Thunderbolt. Internal drives connect via SATA directly to the motherboard.
- External hard drive enclosures contain built-in circuitry and bridge chips to translate between the external connector and the internal drive.
So since external hard drives use external connectors like USB, they do not require SATA ports to connect to a computer. The external connector provides both data transfer and power delivery over a single cable.
Some other key characteristics of external hard drives:
- Most external hard drives use a standard hard drive inside the enclosure, the same kind used for internal drives in computers.
- 2.5″ laptop hard drives are commonly used in smaller external enclosures. 3.5″ desktop drives are used in larger external enclosures.
- The hard drive inside the external enclosure connects to the bridge board internally through a SATA connection or sometimes IDE.
- Popular external hard drive interfaces include USB 2.0, USB 3.0, USB-C, Thunderbolt, eSATA, and Firewire.
- Converting internal hard drives into external drives is straightforward with an external enclosure.
So in summary, the hard drive inside an external enclosure does connect via SATA, but that SATA connection is not accessible from outside the enclosure. The bridge board converts the SATA interface to USB, Firewire or another external interface.
Exceptions: Enclosures With SATA Passthrough
While most external hard drives do not have accessible SATA ports, there are some rare exceptions.
Some higher-end external drive enclosures designed for large 3.5″ hard drives may provide a SATA passthrough or eSATA port connection.
This allows the internal SATA connection to be passed through to an externally accessible eSATA port on the back or side of the enclosure. An eSATA cable can then be connected from the enclosure directly to a SATA port on the computer.
This setup allows the bridging circuitry to be bypassed, connecting the hard drive directly via SATA externally. This can provide slightly faster speeds compared to using a USB 3.0 or Firewire connection through the bridge chip.
However, the market for external SATA enclosures is quite small. eSATA ports are not common on most laptops or motherboards, and eSATA cables are not as convenient to use compared to standard USB cables. Also, USB 3.0 and Thunderbolt now offer comparable transfer speeds to eSATA.
So SATA passthrough on external hard drive enclosures is rarely seen today. But it does provide an option for some specialized use cases that require the highest transfer speeds in an external drive.
Rare Cases: External Drives With Exposed SATA Ports
There are some very rare cases where you may find an external hard drive with an exposed SATA port on the outside of the enclosure.
For example, some models of LaCie big external RAID hard drive systems aimed at professionals have a small exposed SATA port on the exterior.
This allows you to daisy chain multiple LaCie external drive enclosures together by connecting them serially using SATA cables. This is only supported on certain discontinued LaCie models.
You may also infrequently find older external hard drive enclosure models designed for use with laptop hard drives that have an exposed eSATA port. These could connect to a computer via eSATA, but still do not provide a fully accessible SATA connection.
Overall, finding an external hard drive with a directly exposed SATA port on the exterior is extremely uncommon. The LaCie daisy chaining use case represents one of the few examples where this can be found.
Summary
While the internal hard drive inside an external hard drive enclosure will connect via SATA, the SATA connection is not exposed outside the enclosure in over 99% of external drives.
Instead, external hard drives are designed to connect to host computers using external cabling such as:
- USB
- USB-C
- Firewire
- Thunderbolt
- eSATA (very rare)
The enclosure handles converting the SATA connection to these external interfaces, providing plug-and-play connectivity.
So in summary:
- External hard drives do not require or utilize SATA ports, since SATA is meant for internal connections.
- The bridge board handles converting SATA to USB or another external interface.
- A very small number of specialized external enclosures may offer eSATA passthrough or daisy chaining via SATA.
- But overall, external hard drives are designed to connect via USB, Thunderbolt or other common interfaces – not SATA ports.
Examples of External Hard Drives
Here are some examples of common external hard drives that do not have SATA ports:
WD Elements Portable External HDD
One of the most popular and affordable portable external hard drives on the market. It provides up to 5TB of storage in a compact 2.5-inch form factor that only requires a USB cable to connect to PCs and Macs. No SATA connection is provided or required.
Seagate Backup Plus Desktop External HDD
A widely used desktop external hard drive, the Seagate Backup Plus caters to capacities up to 14TB using a standard 3.5-inch internal hard drive. It connects via USB 3.0 and includes backup software. No SATA ports are included, only USB.
LaCie Rugged Thunderbolt Portable SSD
Designed for portability, durability and speed, the LaCie Rugged SSD offers USB-C and Thunderbolt connectivity over a ruggedized enclosure containing a solid state drive. It provides high-speed external storage without the need for SATA connectivity.
OWC ThunderBay 4 Mini RAID Enclosure
This specialized enclosure made by Other World Computing provides support for up to four 2.5-inch SATA drives in a RAID array. It connects externally via Thunderbolt but also includes an eSATA passthrough port for daisy chaining. A rare example of SATA-to-eSATA connectivity in an external enclosure.
Conclusion
In conclusion, the vast majority of external hard drives are designed to connect using USB, Thunderbolt or other common interfaces. They do not require or provide SATA ports externally, though the internal drive will connect via SATA.
Only in very rare, specialized cases would an external drive enclosure provide a SATA or eSATA passthrough or exposed port. So generally speaking, external hard drives do not have SATA ports given the predominance of USB and other interfaces designed for external connectivity.
