What are SATA Ports Used For?

If you are new to PC building and all the technical jargon involved, then one of the first questions that you may ask is what are SATA ports used for and what components use them?

Well SATA ports are basically, used to connect storage devices to your PC. The hard disk drives, optical drives and SATA SSDs all use the SATA interface in order to connect to your system.

SATA is one of two primary interfaces, the other one being PCIe, that is used to add modular characteristic to your PC. While PCIe is used to connect high speed devices, SATA is primarily used to connect internal storage devices.

In the following article, I will talk in detail about what are SATA ports used for.

What are SATA Ports Used For?

At the moment, the SATA interface is used for three primary devices:

  1. Hard Disk Drives
  2. SATA Solid State Drives (SSDs)
  3. Optical Drives i.e CD/DVD/Blu-Ray Drives

Let us cover each one of these individually.

1. Hard Disk Drives (HDD)

Budget Hard Disk Drives
Image: 3.5″ WD Blue – A popular hard disk drive for the budget segment.

Almost everyone is familiar with these drives. These are your large and bulky storage drives that consist of spinning disks and a lot of mechanical parts.

Despite Solid State Drives (SSDs) become more and more wide-spread, hard disk drives are still the run-of-the-mill solution to your storage needs as they are cheaper and offer huge capacities.

They Come in Two Sizes

There are typically two sizes for HDD, aka form factors:

  • 3.5″
  • 2.5″

The 3.5″ drives are often found in desktops, whereas the 2.5″ drives are found in laptops.

2.5″ Hard Disk Drive – found often in laptops – Wikimedia

Hard Disk Drives are Slow

While hard disk drives provide a huge storage for cheap, they are very slow. 

A typical hard disk drive can reach speeds of only about 200 MB/s at best.

As such, compared to the rest of the mainstream drives out there, they are super slow.

A Note on SATA Ports and Their Versions

It should be noted that there are different versions to the SATA protocol. 

The latest and the current generation of SATA is 3. With each new generation, SATA doubles its transfer such that:

  • SATA 1 has transfer speed of 1.5 Gbps or 187.5 MB/s
  • SATA 2 has transfer speed of 3.0 Gbps or 375 MB/s
  • SATA 3 has transfer speed of 6.0 Gbps or 750 MB/s

As far as the typical hard disk drives are concerned, with transfer rate of about 200 MB/s, they hardly saturate the SATA 2 interface, let alone SATA 3.

Simply put, it is just not mechanically possible for hard disk drives to saturate SATA 2 or 3 ports.

Also Read: How to Identify What Version of SATA You Have?

2. SATA Solid State Drives (SSD)

SATA SSD
SATA SSDs connect to SATA ports unlike NVMe SSDs that connect to the PCIe interface

Another popular component SATA ports can be used to connect are the SATA SSDs.

SATA SSDs that connect directly to the SATA ports have a 2.5″ form factor as shown above.

SATA SSDs benefit directly from a SATA port with a higher transfer speed.

SATA 3 SSDs have a typical transfer rate of about 550 MB/s. However, if you were to install these on a SATA 2 port, then their transfer speed can be slashed by half thus significantly hindering their performance.

Also Read: Does it Matter Which SATA Port I Use?

SATA SSDs Not To Be Confused with NVMe PCIe SSDs

Often people get confused between the two, however, the difference between the two is drastic.

SATA SSDs use the SATA interface and thus SATA interface serves as the bottleneck. 

In other words, a SATA SSD is currently limited by the maximum transfer speed of the SATA 3 interface (which is 750 MB/s).

NVMe SSDs, on the other hand, use the PCIe interface and thus they are stupendously fast compared to any other storage method.

A Gen 3 NVMe SSD can have a transfer speed of 3500MB/s. A Gen 4 NVMe SSD, such as the Samsung Pro 980, has a typical transfer speed of about 5500 MB/s.

NVMe SSDs have the M.2 form factor.

The following article may also help in understanding the subject further:

M.2 SATA SSD
What are SATA Ports Used For
Samsung Evo 860 SATA SSD with M.2 form factor

You can also find SATA SSDs in the M.2 form factor which go into the SATA compatible M.2 slots on a motherboard.

While they share the same SATA interface as the 2.5″ SATA SSDs do, they DO NOT plug into the SATA ports, but instead into the M.2 port.

The following table summarizes the typical speeds of various drives:

Storage Type
Read Speeds
Hard Disk Drive 200 MB/s
SATA SSD 550 MB/s
Gen 3 NVMe SSD (PCIe) 3500 MB/s
Gen 4 NVMe SSD (PCIe) 5500 MB/s

Hence, given the tremendous speeds achievable by the NVMe SSDs, SATA SSDs aren’t as popular. 

NVMe SSDs can cost more than a SATA SSD, however, the performance gains are phenomenal and well worth the money.

crystal magic disk speed comparison
Image: Seagate 3TB BarraCuda SATA vs Samsung SATA SSD 850 EVO vs Gen 3 Samsung 970 EVO NVMe SSD Source/Credit: Jollibeee86 Reddit

Also Read: Is SATA 3 Compatible with SATA 2 Ports?

3. Optical Drives (CD / DVD / Blu-Ray Drive)

cd drive
Optical Drive. Image Source: Wikipedia

Finally, SATA ports are used to connect optical drives such as the CD, DVD and Blu-Ray drives.

Optical drives have more or less been phased out from PCs, particularly from laptops.

Compared to the rest of the drives, optical drives generate the least amount of data as they are limited by the transfer rate of the disc inserted.

For instance, the fastest 24x DVD disc can have a maximum transfer rate of about 32 MB/s, a 16x Blu-Ray disc caps at 72 MB/s.

This is far lower than the 750 MB/s speed cap of the SATA interface.

CD and DVDs used to be the preferred medium of information transfer back in the days.

However, they have almost completely been replaced by USB drives and the internet. 

The sustained transfer speed of a typical USB 3.0 flash drive or an external hard drive is about 85 MB/s – far greater than a DVD and also greater than a Blu-Ray drive.

Also Read: Can You Use a Laptop Hard Drive in a Desktop?

SATA Drives Require Both a DATA Cable AND a SATA Power Cable

Desktop PC builders must beware of the fact that SATA Drives require both a SATA Data Cable as well as a SATA Power Cable in order to operate.

SATA Data Cable are provided with the motherboard, whereas, the SATA Power Cable come with the Power Supply Unit.

They both have their separate notches/plugs for where they need to go on the drive. 

Sata Power Cables
SATA Power Cable – comes from the Power Supply Unit
sata data cable
SATA Data Cable – has identical two ends. One connects to the motherboard SATA port and the other connects to the drive.
hard drive ports connections
Shows where you would insert the cables

Final Words

So to reiterate the answer to the question “what are SATA ports used for?”, essentially, they are used to connect SATA based storage drives which include hard disk drives, SATA SSDs and optical drives.

Note that each SATA port connects to only a single drive. You can also expand the number of SATA ports you have on your motherboard by adding extra expansion card on the PCIe slots. You can read about this here: How to add more SATA ports to Motherboard?

Also Read: What are USB Headers?

Photo of author

Author:

Atif Qazi
Atif Qazi is the founder of PCGuide101. He is a digital nomad who loves everything PC. He is a PC builder, tech enthusiast, engineer, and a lover of single player lore-rich RPG games.

Leave a Comment