Fact Checked

What is eSATA?

R. Kayne
R. Kayne

External Serial Advanced Technology Attachment or eSATA is an external interface for SATA technologies. It competes with FireWire 400 and universal serial bus (USB) 2.0 to provide fast data transfer speeds for external storage devices.

SATA replaced ATA legacy technology as the next generation internal bus interface for hard drives. The SATA interface is more streamlined than ATA and provides serial architecture for greater speed than the older parallel technology. eSATA cables are narrow and can be up to 6.56 feet (2 meters) in length, whereas parallel cables are much wider and limited to a length of 18 inches (45.7 cm). With eSATA, the speed of SATA expands to encompass exterior storage solutions.

An eSATA card.
An eSATA card.

While eSATA reaches transfer rates of at least triple those of USB 2.0 and FireWire 400, it does have one drawback. eSATA requires its own power connector, unlike the aforementioned interfaces. It is still an excellent choice for external disk storage, however. Unlike USB and FireWire interfaces, eSATA does not have to translate data between the interface and the computer. This enhances data transfer speeds, while saving computer processor resources and eliminating the need for an extra off-load chip.

A computer motherboard.
A computer motherboard.

For desktop motherboards that don't have an eSATA connector, a peripheral component interconnect (PCI) card can be purchased and installed in an available PCI slot that will provide an eSATA interface. Notebooks can use an external eSATA device made for the PCMCIA, PC Card, or ExpressCard slot, depending on the laptop model. eSATA enables use of fast SATA drives for external disk arrays, not only expanding valuable storage real estate, but also enabling truly fast portable storage. eSATA's hot-swappable feature makes taking disks from work to home, or from one computer to another, easy. Administrators, IT techs, advertising and marketing executives, and even gamers may find this beneficial.

eSATA competes with FireWire 400 and USB 2.0.
eSATA competes with FireWire 400 and USB 2.0.

SATA has differing standards, with older hardware supporting the original standard exclusively. With each new SATA iteration, speed increases. Original SATA, or SATA 150, has a data transfer speed of 150 megabytes per second (MB/s). SATA 3G doubled the speed to 300 MB/s or about 3 GB/s. This is also sometimes referred to as SATA 300.

When purchasing an eSATA controller or bus card, be sure it supports the SATA standard required by your SATA hard drive(s). Hardware that supports newer standards is usually backward compatible with older devices, but the reverse does not hold. An eSATA controller made for SATA 150, for example, will not be able to support the faster transfer speeds of a SATA 300 hard drive.

What Are eSATA Ports?

What is an eSATA port? eSATA, or external SATA, ports are a type of interface used for external hard drives that use SATA technology. Like FireWire 400, IEEE 1394, and USB, it allows for rapid data transfer speeds for external storage drives.

SATA 6Gb/s matches the speed standard of USB 3.0, introduced in 2008.
SATA 6Gb/s matches the speed standard of USB 3.0, introduced in 2008.

SATA is the successor to ATA for internal bus interfaces. In addition to having faster speeds, compared to parallel ATA cables, eSATA cables are far narrower and easier to manage. They can also be longer: an eSATA cable can be up to 6.56 feet, or two meters, long, but a parallel ATA cable can only be 18 inches, or 45.7 centimeters, long.

eSATA does not require any sort of data translation between the computer and the interface, which allows for speeds of up to six times that of USB 2.0, IEEE 1394, or FireWire 400. eSATA has a strong speed advantage, but this comes at the cost of needing an external power connector. In other words, you have to plug eSATA devices into the wall before they can function.

One advantage of eSATA is that devices that take advantage of this technology are hot-swappable, meaning they can be disconnected and reconnected easily, similar to a USB drive. This allows for efficient and speedy data transport, such as what you might need if you want to bring data from work to home or vice-versa, or if you just want to move data between drives easily.

How To Use eSATA

Using eSATA is as simple as connecting two devices that support the technology together and transferring data like you would between any other modern storage device. If you’ve ever transferred data between storage devices, you’ll know how to use eSATA.

For eSATA to work, it requires an eSATA port on the motherboard. Note that this is not the same thing as a SATA port, so don’t try connecting an eSATA cable to a SATA port. If your motherboard does not have an eSATA port, you can install a peripheral component interconnect card that expands your motherboard’s capabilities.

There are multiple versions of SATA, so make sure your devices are all using compatible types. The most recent version of eSATA is eSATA 600 or 6 Gbps. Newer types of SATA are backward-compatible with older interfaces, but you will be limited to speeds of the lowest version you’re using. For example, if one device uses SATA 300 and another uses SATA 600, you will only get SATA 300 speeds.

While eSATA interfaces are hot-swappable, this does not mean you should disconnect a device while data transfer is in progress. Doing so risks data loss.

Should You Use eSATA or USB 3.0?

When eSATA was first released, it was vastly superior to the existing technologies of USB 2.0 and FireWire. However, with the introduction of USB 3.0, the playing field has changed. USB 3.0 has massive advantages over its 2.0 counterpart, including remarkably faster maximum transfer speeds and being able to act as its own power connector. USB 3.0 also introduces the technology of Bulk Streams, which makes it so multiple data stream transfers can occur at the same time. This means that large files such as HD videos can be transferred far quicker than they could on USB 2.0, which was not designed with particularly large files in mind.

On the most basic level, the most modern version of eSATA beats USB 3.0 in raw maximum transfer speeds, with USB 3.0 having a maximum transfer rate of 5 Gbit/s and eSATA clocking in at 6 Gbit/s. However, this does not mean eSATA is superior or better for your needs, as maximum speeds rarely reflect practical speeds.

The technologies underlying each interface are vastly different and one is not necessarily superior to the other. According to one test, with an external hard drive, USB 3.0 is 20% faster than eSATA at read speeds, but eSATA has superior write speeds, being about 20% faster than USB 3.0 on this measure. In addition, USB 3.0 devices generally do not need an external power connector.

Some external hard drives contain both a USB and an eSATA interface and you will probably get the same transfer speeds for the same hard drive. Generally, the speed will be more limited by the external hard drive itself than the type of interface used. Use whichever interface is more convenient for you.

Your experience may be different, as practical speeds can vary wildly between devices and interfaces. As with all newer technologies, both eSATA and USB are still in development and new versions of each will undoubtedly be released as time goes on.

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Discussion Comments


Can you transfer files from one machine (PC) to another (Laptop) using eSATA? Is there a different type eSATA cable necessary to connect the two machines? I have the ability to run crossover, but then I lose my Internet connection on both machines.


Which is better: 2TB SATA or 1TB Serial ATA Drive or 1t fusion?


My DirecTV box has an esata port. Can I run an external sata 1tb drive and still use the drive that's in the receiver?


@Beatslave1: Check your motherboards manuals to see if it supports eSATA. If not, you will need to purchase a PCI or PCIe Esata card. Though, I'd say if your mobo is PCI only, there wouldn't be a huge need for eSATA. - Tommosimmo


I have recently converted my external HDds to esata, even though it is only esata I. what a great surprise.

Will need a new laptop with express card slot to go to esata II. I am using a 54 mm pcmcia esata card from vantec, and a 2TB data dock from fantom hard drives. system works flawlessly once drives are formatted, and run three times faster than my laptops hard drive. I'm throwing all my usb cables away. --warm and dry in ABQ


Actually, some eSATA ports ARE hybrid eSATA/USB ports. My Alienware M15X has one.

Providing that you have a combo port (look for both the text "eSATA" and the USB logo on the port you've been told you can use, and you should be able to.

The first time I plugged a USB cable into my hybrid port, it was a little stiff and took a few moments, but it did work.


Manyhats: if you want to connect a backup drive, just get a time capsule or two for the company. it is easier and faster than finding an eSATA card.


@anon121511: If you use the Delock eSATAp (power over eSATA) cable or enclosure, just ONE cable will be enough. Note you can only connect up to 2.5" as notebook only supply 5v as compared to desktop (up to 3.5" due to 12v).

Please also confirm that your notebook eSATA port is eSATA. How to know? Simply plug in a usb port into the eSATA port. If the eSATA port can allow USB, it is an eSATA port. Usually 90 percent of the notebooks from Dell, Toshiba, Sony, HP and Lenovo use eSATA ports. I have seen rare cases when MSI uses the older eSATA port.


I have hard disk drive which is sata. I want to connect it to my laptop to read its information. Can do it by connecting it to my laptop's eSATA external port? in other words, is just one cable enough to do that? do I need power or any other thing?


The longer the cord the longer it takes for the data to get to its destination. Not only that but some of the data does degrade or you even lose data in the process.


eSATA and SATA is can be hot swap whether you have AHCI OR not. Intel or VIA chipset.

FAQ and understanding

1) eSATAp is eSATA + USB SATA is USB backward compatible. SATA is also known as SATA on the Go by Asus and Power over eSATA by MSI.

2) SATA can be found on almost 40 percent of new notebooks. So please ask for a SATA HDD, not eSATA.

So far, I only know Delock and Lacie produce SATA cables and enclosures.

3) Forget what you have learned about BIOS AHCI or Windows registry tweak. SATA CAN be easily implemented on ANY desktop/mac pro with just a DELOCK bracket. Zero drivers; it's plug and play.

4) SATA can supply 5v to power up a 2.5" HDD/SSD or 12V(MAC Pro/Desktop) to power up a 3.5" HDD/SSD or DVD-RW using just one cable.

5) eSATA can be found in NAS to expand storage.

6) As of now SATA is still faster than USB 3.0 due to minimum translation and overheads.

7) MAC users can use SATA as a Final Cut and Adobe scratch disk.

8) Other applications of SATA includes high speed data recovery, disk cloning, virtualization (virtual machine) on external disk, etc. --Colin L.


For all of you whom are unsure of what disk management is, who don't know how to assign a drive letter, who don't know what device manager is, who are unsure how eSATA works, who don't know what AHCI is *do not* assume that eSATA is as simple as USB!

If your SATA controller does not support hot-swapping or advanced host controller interfaces eSATA will not be hot-swappable (hot-plug/plug and play). If you don't know how to check this USB is your best bet.

Advice from retail eletronics stores (where you buy computers, fridges, toasters, vacuums all in the one store) is generally *incorrect* as seen above with comment 29 by anon40431. USB *is not* eSATA! A USB cable will NOT fit in an eSATA socket and vice-versa.

If you want correct advice and support buy your computer electronics from specifically *computer-based stores.* The same guy in the retail store who sells the toasters will occasionally be stuck in the IT department when those guys call in sick. Anyone can get a retail job. IT careers require training and qualifications!

See you local reputable IT *specialist* if you have any questions regarding the purchase and use of an eSATA device or caddy.


In windows XP I tried converting my external e-sata disk to be "Dynamic", supposedly making any disk Dynamic makes it hot-swappable. I'm not totally convinced of that.

In XP I was able to plug in the drive and fudge around in the Disk Management window to get the disk to show up after many clicks. The same to unplug it. So it was "plug-and-play" but definitely not convenient, quick, or user friendly to do.

Then when I tried to connect my dynamic disk to my cousin's Vista laptop via USB (his laptop has no sata port) it was impossible to get it to show up. I couldn't even find a way to do it through the disk management window.

Based on my experience I say for maximum compatibility do not make your external sata disk a Dynamic Disk.

When you know you need maximum speed, accept that you will need to shut-down, plug in the esata, and start up.

When you need to run around from one computer to the next with you drive (friends, neighbours, work, home, grandma, win98, win2k, winxp, vista, 7, os-x, ubuntu, linux, etc) then you will be so glad that you external drive also has the USB option.


eSATA is great, but watch your cable lengths!

Any more than three feet and performance (transfer speeds) degrade rapidly.


I have an asus MB with SATA no ESATA port. I purchased an ESATA cable which basically plugs into the sata on the MB and then has the ESATA connector on the other end.

I have a external HD with ESATA and a sata drive installed when I connect, but when all connected it doesn't seem to work. is E-sata plug and play? should it auto detect? do I need to run the hardware wizard the external works with the usb but not the esata.


I just purchased a Buffalo 1TB eSATA drive and it mounted first try on my Vista 64 based system. The transfer was so much faster than USB 2.0 that I was quite pleased with my choice to go with the more expensive drive. The drive also interfaces with USB and Firewire. Good luck guys!


I have a seagate barracuda 1200.9 (eSATA) and it seems that the PCI board is faulty. I purchased a SATA casing but it does not seems to work. (1) the casing for eSATA and SATA is different? (2) Can the PCI board on the disk be change?


"doubled the speed to 300 MB/s or about 3 GB/s"- this is really going to throw off some people.. 300 MB/s is about 3Gb/s (the lower-case b), because 300MB/s and 3GB/s are not anywhere near the same. Even more confusing is why they call it 3Gb/s when it's really closer to 2.5 but I guess that's the way it goes.


I have a Thermaltake Blacx duet, a device that allows me to hot swap interal sata drives. It can be attached to the computer with either USB 2 or Esata. I copied the first two disks using USB2 and it was of course very slow. I finally got hold of cord that runs from an empty Sata port to an esata device. I hooked it up and am formatting my first disk with it and it's taking twice as long as it did with the USB2. Any thoughts?


i cannot connect a USB plug (ex. flash storage) to esata port on acer revo n3600. the salesman confirmed that i should be able to plug it in, but it does not fit? is there anything that i should do before inserting the usb plug?


What's the best way to attach a 3.5" WD 750GB SATA-II drive externally to an xp system?

2 Cheetah in RAID 0

1 WD 250 GB to SATA

The only cost-effective solution that I've found is a HDD docking station with an internal SATA-II connector and a USB 2.0 and eSATA external connector. I can use an eSATA bracket cable that does not use a PCI board but is fastened to the case similar to a board and uses a cable with a SATA connector on one end and an eSATA connector on the other. The HDD docking station comes with an eSATA cable in addition to a USB cable. Might I run into any problems with this configuration? In addition, should I be concerned with incompatibilities? That is, are there different types of SATA cables and might selecting the wrong cable(s) degrade performance?


Can I install OS on ESATA hard disk?


my external hard drive is not working anymore..can i get all my data through e-sata? if yes how? because i don't know what e-sata is used for. pls help thank u.


I want to put an os on a Esata drive. Can I do this and how? What is an Esata rom?


Hi, I had a funny problem with connecting an e-sata hard disk to a portable computer under Vista:

I connected the disk, it was visible with the administration tools, but would not appear on Windows Explorer.

I found I had to manually define the drive letter for this disk - once I had done so it worked.

Maybe this can help!


This is probably stated somewhere on this page, but I just want to make sure of this, as I am not the most technically adept person

If i wanted to use an eSATA connection for an external hard drive, would I need anything other than the cable to use it?


We have iMacs for our business and want to include and external drive for backing up files separate from our server. Is there a bus card for Macs and hard drives with eSATA or is it not worth bothering with?


just go back to xp....only thing to do


What a great idea e sata is! If only it worked. I can't get Vista to recognize my new external drive and the web is full of postings from others with the same problem and no answers.

Has anyone managed to get Vista to back up to an external e SATA drive yet? If so I'd love to know how to do it.


To connect an eSATA external drive, you can buy an eSATA PCIe card and an eSATA cable from your retailer or amazon to use the eSATA features of your drive.


I use an external SATA drive for my DVR and typically it will not record the entire show. Or after recording instead of 60 min recorded it shows 15 to 40 min recorded. Is this due to the external drive? I have swapped external cases and drives. still the same thing.


Can I connect external HD with eSATA interface to the MB SATA connector with a cable that one side with SATA connector and the Ather side is eSATA connector?


Most external SATA drives that also support USB seem to not be designed for SATA speeds. I have tested 3 that seem only to do about 25MB/sec. connected to a PCI express card. My guess is the FPGA designs are based on USB and they didn't go that extra mile for SATA speeds throughout the external drives' architecture.


I want to purchase an external hard drive to clear up space on my dvr. It seems like a drive with eSATA interface would be most efficient. I was wondering if anyone could explain to me how one could then transfer that data from a the external drive, through a pc and then burn to a disc? Is there some way this can be done and also somehow translate the HD programming to a disc as well?


I have found out that if the transfer of large amounts of data is what you're doing then ESATA is what you need. Your MB needs to be ESATA compatible meaning there should be a ESATA plug on the back of your PC so the ESATA cord from your ESATA HDD can plug into some MB have more than one, like the high end Dual Core MB and many of the Quad Core MB Intel or AMD. I believe that because our computers are doing more than just surfing the Web IE. Gaming, Blueray, Movie downloading (Blockbuster) to name a few, HDD are bigger than ever for the home PC and moving that amount of data smoothly makes ESATA the answer for external HDD now.


SATA and eSata cable connectors are different (eSata adds shielding to their cable and doesn't want you to mess up by plugging and unshielded cable into your eSata device) eSata has a max transfer rate of 3000mb/s and firewire800 has a max transfer rate of 800mb/s


Is eSATA (external HDD) compatible with ulrta ata/100 (notebook)?


If I understand this ESATA correctly....... ESATA will allow me the ability to connect two three four external HDD using the ESATA cables but each HDD needs its own power supply and the motherboard has to be ESATA compatible.


Are the connectors for SATA and eSATA compatible?


What are differences between eSATA and Firewire 800?


eSata is a new option on new motherboards. Your board has to be able to run eSATA otherwise it won't even detect it; usb and firewire are your only options. The speed difference is crazy. It took all night to copy 295gb and it only took 2 hrs via 2 eSATA drives!!!! Go eSata!


any HDD SATA can be plug in to eSATA slot and can be hotplug at anytime?


hi there,

I just purchased a Seagate Free Agent Pro external hard drive and i was wondering if anyone knew if the eSATA option would work with my PPC G4 MDD? I was just planning to use the firewire 400 but noticed this other option. Are there huge advantages? Will I need other items such as PCI cards as well? Hit me when you can.



I have a Dell Dimension 8200. I was just in contact with Dell support. They seem to think I have to use eSATA HD with USB 2.0 port. Can you recommend a card that I can use so that I can install an external SATA drive?

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    • An eSATA card.
      By: RomainQuéré
      An eSATA card.
    • A computer motherboard.
      By: VIA Gallery
      A computer motherboard.
    • eSATA competes with FireWire 400 and USB 2.0.
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      eSATA competes with FireWire 400 and USB 2.0.
    • SATA 6Gb/s matches the speed standard of USB 3.0, introduced in 2008.
      By: Shawn Hempel
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