What Does SATA 6Gb/s Mean?
SATA 6Gb/s is the third-generation of SATA, the predominant interface standard for connecting a computer’s host bus adapter to data storage drives. Specifically, SATA 6Gb/s ports are used to connect the motherboard to data storage units such as hard drives, solid state drives, and optical disc drives. Although the terms are technically incorrect, SATA 6Gb/s is sometimes referred to as SATA III or SATA 3.0, as it is the third revision of the SATA interface.
SATA stands for “Serial ATA” or “Serial Advanced Technology Attachment.” The “6Gb/s” refers to the fact that this SATA version supports maximum data transfer speeds of 6 gigabits per second, which is twice the speed of the previous generation (3 gigabit per second). Regardless of their generation, SATA cables have a maximum length of one meter (3.3 feet) and connect a motherboard socket to a single hard drive.
Serial ATA (SATA) vs. Parallel ATA (PATA)
When it was introduced in 2000, SATA technology changed the landscape of hard drive technology by switching from wide Parallel ATA (PATA) data cables and connectors to narrow serial cables and connectors, paving the way for faster speeds than parallel technology could handle. The use of SATA cables also physically reduced obstructions inside computer cases, thus allowing for greater air flow, faster computer processing units (CPUs), and higher capacity disk drives.
Other advantages over PATA include more efficient data transfer, lower power requirements, and greater affordability, as SATA requires far fewer conductors than PATA. Unlike PATA, SATA also features hot plugging, allowing computer users to add or remove devices while the computer is running. SATA has now replaced PATA in nearly all laptop and desktop computers.
Revisions to the SATA Interface
- The first revision of SATA, also known as SATA 1.5Gb/s (or incorrectly as SATA I or SATA 1.0), was released in 2003. SATA 1.5Gb/s interfaces communicate at a native transfer rate of 1.5 Gb/s. This equates to a maximum uncoded transfer rate of 1.2 Gb/s, or 150 MB/s. Initially, the fastest PATA interfaces (such as PATA/133) could compete with SATA 1.5Gb/s, but PATA was reaching the limits of its clunkier architecture, whereas SATA was undergoing further improvements.
- Released in 2004, the second generation of SATA was SATA 3Gb/s (erroneously referred to as SATA II or SATA 2.0). Second-generation SATA technology, which is backwards compatible with legacy SATA systems, doubled the native transfer rate to 3 Gb/s and the maximum uncoded transfer rate to 2.4 Gb/s, or 300 MB/s. Notably, SATA 3Gb/s introduced Native Command Queuing (NCQ), which was not supported by SATA 1.5Gb/s.
- The third revision of SATA, known as SATA 6Gb/s, was released in 2009. The third-generation of SATA technology supports transfer speeds up to 6Gb/s, which is equivalent to a maximum uncoded transfer rate of 4.8 Gb/s, or 600 MB/s. SATA 6Gb/s has doubled the theoretical burst throughput of SATA 3Gb/s, while still remaining backwards compatible with SATA 3 Gb/s and even SATA 1.5Gb/s, as it uses the same cables and connectors. Other improvements in SATA 6Gb/s relate to additional NCQ commands and improved performance of high-bandwidth applications, such as video streaming quality. Although further fine-tuning of the SATA 6Gb/s standard has occurred over the last decade, SATA 6Gb/s remains the most recent generation of architecture.
Is the SATA 6Gb/s Interface Compatible with Older Ports?
As previously mentioned, SATA 6Gb/s is fully compatible with previous generations of SATA technology, including motherboards that support the SATA 3Gb/s or SATA 1.5 GB/s interface. However, you should be aware that the maximum read and write speeds of a SATA 6Gb/s drive are likely to be reduced when connected to a SATA 3Gb/s or SATA 1.5 Gb/s port.
In some cases, you may be able achieve comparable transfer speeds with both SATA 6Gb/s and SATA 3Gb/s cables. Sometimes, the quality of the cable and the materials used may be just as important as the SATA specification.
A quick note about terminology:
The Serial ATA International Organization (SATA-IO), which designs and manages SATA standards, has requested that the third-generation of SATA be referred to as SATA 6Gb/s, rather than SATA III or SATA 3.0, in order to avoid potential confusion with the second-generation of SATA, which is officially known as SATA 3Gb/s, in reference to its transfer rate.
What Is SATA and What Is It Used For?
As a popular and ubiquitous interface meant to connect a computer’s host bus adapter to data storage drives, SATA is the predominant way to attach a multitude of devices to a computer motherboard. Motherboards that use SATA often come packaged with SATA cables, and they can also be purchased separately.
SATA is the common interface used for both solid-state drives and hard disk drives, as well as optical disc drives.
What Does SATA Stand For?
SATA stands for Serial ATA or Serial Advanced Technology Attachment.
What Is SATA vs SATA III?
The first variety of SATA came about in 2000. The first revision was called SATA 1.5 Gb/s and came about in 2003. As you might safely guess, it had a native transfer rate of 1.5 Gb/s. It was designed as an alternative to PATA, or Parallel ATA.
SATA 3 Gb/s came about soon afterward in 2004, doubling the native speeds of the previous version. SATA 3 Gb/s was backward compatible with SATA 1.5 Gb/s, so you didn’t need a new motherboard if you were still using devices designed for SATA 1.5 Gb/s. One special feature that SATA 3 Gb/s had was Native Command Queuing, which allowed the drive to prioritize read and write commands. In the previous version, these requests were always done in the order in which they were assigned.
In 2009, the third version of SATA came out: SATA 6 Gb/s, which doubled the native transfer speeds again and added new NCQ features, and improved performance for demanding tasks such as video streaming. This third revision is sometimes called SATA III, though the Serial ATA International Organization prefers this term not to be used so as not to cause confusion between SATA III and SATA 3 Gb/s. SATA 6 Gb/s was backward compatible with both previous versions of SATA. You could use a SATA 6 Gb/s interface with a SATA 1.5 Gb/s device, though the transfer speeds would be throttled to 1.5 Gb/s. If you wanted 6 Gb/s speeds, you needed both the interface and device to be compatible with the 6 Gb/s versions.
Can You Get 6 Gb/s Speeds With a 3 Gb/s interface?
It is sometimes possible to get improved speeds despite the different interfaces if the quality of the cable is high enough. The attributes and materials used in the cable can sometimes be more important than which version of SATA is being used.
Which Version Is Appropriate for Hard Disk Drives?
Hard disk drives typically do not need anything higher than SATA 3 Gb/s to function at maximum speed. Modern hard disk drives typically don’t support read speeds higher than 200 Mb/s. SATA 3 Gb/s supports read speeds of up to 300 Mb/s, so a 3 Gb/s interface should work well.
Which Version Should I Be Using for Solid State Drives?
SSDs have considerably faster data transfer speeds than traditional hard disk drives, so you may wonder whether you will see a noticeable difference with newer versions of SATA. The answer is: Not usually. A SATA 3 Gb/s interface is usually perfectly adequate for use with an SSD, and a normal user is unlikely to take advantage of the extra bandwidth in a 6 GB/s interface. Thus, if your motherboard only supports SATA 3 GB/s and you want to use an SSD, you will probably not need to upgrade.
However, if your SSD is designed for SATA 6 Gb/s, you may not be getting optimal speeds with a 3 Gb/s interface. Check with the SSD manufacturer if you’re not sure which version you should use, or just use a 6 Gb/s interface to be safe.
Which Version Is Right for Optical Drives?
Generally, all versions of SATA are adequate for optical drives, whether your optical drive is designed for Blu-ray, DVD, or CD. None of these drives have particularly high read and write transfer speeds even at their maximum speed.
How Do SATA and PATA Differ?
SATA and PATA cables look vastly different on the outside, with SATA cables being far narrower thanks to their needing fewer conductors on the connector. By comparison, PATA cables are thick and bulky, which took up valuable space in a computer case and trapped heat. Because SATA cables were able to reduce heat in a computer case, faster CPUs and higher-capacity disk drives could be installed safely.
On the inside, SATA cables have lower power requirements and better efficiency during data transfers. Finally, the SATA interface is less expensive than PATA.
When a manufacturer says a drive will reach 6Gb/s that means 6 gigaBITS, not bytes! That translates to 600 megaBYTES per second. Hard (platter) drives cannot reach that speed on their own. Manufacturers are engaging in false advertising and while lately they have been putting the words "up to" on them, they are still misleading consumers!
I have a new 2TB seagate sata drive that is SATA 6 Gb/s. But my Intel Rapid Storage Technology service shows that the drive is running at 3 Gb/s. How can I configure it differently to run at 6 Gb/s?
I can only agree with the above, however here are my thoughts about solid state drives. It is a fact that these drives will be the fastest drives on the market. My concern is their lifespan. As we know, SSD cards are limited to their total number of writes to one cell. The same applies to the solid state drive. To my knowledge, there is a certain algorithm used to ensure, let's say a round robin is used to spread the write cycles. Whoever constantly updates the data will probably be very unhappy. The drive will run out of life fairly soon. Unless this is a reasonably long time, it's simply not ready.
@scienceguy34 >> Wrong, because usb has a total of 6GB/s for all devices whereas SATA will have 6GB/s for each device.
In fact speeds of SATA 6 are not even adequate for the current drive controllers from SandForce. They have just blown past the top speed of SATA 6 with their newest SF-2000 chip. Now everything is going to go through the 4 Lane PCI Express connector on the motherboard 4x PCIe here we come.
@mcsquare: Ditto on the SSD drives replacing the traditional platen hard drive. It’s already happening.
Personally, I think the fact that the new version of USB is essentially equal in bandwidth to SATA 6Gb/s will end up making SATA 6Gb/s obsolete. Instead of having SATA connections on the motherboard, there will just be more USB 3.0 sockets to which internal hard drives can be connected to—after all, USB 3.0 will have all of the capabilities that SATA 6Gb/s will have, possibly even more.
Consumers generally demand that their devices become more universal and more compatible with other technology, which necessitates a small number of connection protocols. If there are two equal protocols for attaching a device, one of them will dominate the other rather than both coexisting.
@AstroTurf >> True, traditional hard drives made out of platens, or metal disks, have inherit limitations to their speed. However, solid state disk drives have already pushed the current SATA speed limitations to the edge.
In the next decade, you will see the SSD (solid state disk) play a huge role in computing and will eventually replace the traditional platen hard drive. Solid state disks absolutely need a protocol like SATA 6Gb/s in order to reach their full potential.
This is another example of technology getting ahead of itself. The limits of transfer bandwidth are already limited by how fast the hard drive platens can spin. Even in a 10,000 rpm hard drive, the transfer rate will not have the potential to get anywhere near the current SATA limitations.
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