Would you like to know the major differences between SAS and SATA? If yes, then you are at the right spot. Often, many students would like to explore SAS vs. SATA. So, to help them all, here, in this blog post, we have discussed the major differences between SAS and SATA.
Basically, SAS and SATA are connectors that are primarily used for connecting the components of the computer to motherboards such as media and hard drives. However, SAS-based hard drives are faster and more reliable than SATA-based hard drives. Usually, SATA drives provide high storage capacity. As SAS drives are quick and dependable, they are widely used for servers. But SATA drives are inexpensive and utilized for personal computing.
Continue reading this blog post to know more about SAS vs. SATA. Before getting deeper into the differences, first, let us see a quick overview of SAS and SATA storage.
What is SAS?
SAS is an acronym for Serial Attached SCSI or Serial Attached Small Computer System Interface. It is the latest evolution of the SCSI interface drives that are used in servers and higher-end workstations. Similar to consumer computers, a lot of current servers utilize HDD or SSD drives, but they are faster and more reliable.
What is SATA?
SATA is an acronym for Serial ATA or Serial Advanced Technology Attachment. It is the latest evolution of the ATA hard drive and is widely used in PC desktop computers. Nowadays personal computers come with SATA-III or SATA-II ports and SSD drives are common.
SAS vs. SATA: Advantages
Here let us have a look at the advantages of SAS and SATA storage.
Advantages of SAS Storage
Faster Throughput
In a fraction of the time, SAS drives can read/write and process data more than SATA drives. Especially, for random read/write with the new 12 Gbps disks and RAID hardware controllers and for sequential data, SATA is good. But it is not good at random IOPS.
Suitable for 24/7 workloads
SAS is designed for servers and it frequently has 100% duty cycles. Also, it is capable to read/write data every day. But SATA drives are designed only for desktop computers and it has only 20-30% duty cycles.
Advantages of SATA Storage
Cheaper
When compared to SAS drives, SATA drives are 75 % less expensive. Therefore, several hosting companies offer more storage space at minimum prices or at a larger profit margin. Consumers that have a dedicated server can get the benefit from extra storage, such as backup drives.
Faster
SATA is excellent at writing data in sequential order. Overall, it has a throughput of 6 Gbps and it can also write at that rate if there are no random reads/writes.
Good storage capacity for less frequently accessed data
As SATA reads/writes in sequential order, a large RAID-protected SATA-based array will work sufficiently. Hence, SATA is considered the best for storing files, pictures, videos, and backup snapshots.
SAS vs. SATA: Disadvantages
The following are some common disadvantages of SAS and SATA.
Disadvantages of SAS Storage
Less storage capacity
SAS disks come only in smaller size formats with less storage capacity than SATA. Usually, SATA is preferable for backups, file storage, and data archives. But SAS is good for storing only production website content.
Some common SAS storage sizes are 73GB, 146GB, 300GB, 450GB, 600GB, 900GB, 1.2 TB, and 3.8TB.
Costly
When compared to SATA drives, SAS drives are four times costlier. The price of the SAS enterprise starts at $1/ GB. This is why many hosts only provide SATA for dedicated servers.
Consumes More Electricity
The electricity consumption is higher in SAS than in SATA. In comparison to an ATA disc or SATA disc, a SAS requires at least twice as much signaling voltage. If electricity consumption is high, then the operating expense will also increase.
Disadvantages of SATA Storage
Poor random read/write performance
The overall performance of random read/write is bad. In SATA, storage is delayed. Even random read/write requests make the SATA drive crawl
Uses the CPU
SATA does not have an enterprise-class management system like SAS. The data flow management through SATA is delegated to the CPU. Therefore, disc I/O has more influence on the system load average.
Usually, SAS follows command queuing that is significantly faster. But while using shared hosting, the SATA server will be sluggish.
Short MTBF
SATA drives have a lower Mean Time Before Failure (MTBF) than SAS drives. A standard SATA drive lasts 700,000 hours at a relatively cool 25 °C whereas a SAS drive last 1.2 to 1.6 million hours at a warm 45 °C.
Slow RPM
SATA has slower Revolutions per Minute (RPM) and thus has an effect on performance. If a disc rotates faster, then the data can be read or written faster. Generally, a consumer-level SATA operates at 5400-7200 rpm and enterprise-class SAS operates at 10000-15000 rpm.
SAS vs. SATA: Other Major Differences
Basically, there are several differences between SAS and SATA. Here, let us have a look at some key differences.
Speed
Throughput is referred to as the quantity of data that can be read, processed, or transferred and written in a certain time length. In order to determine drive speeds, drive throughput is measured or benchmarked. SAS hard drives often have better throughput than SATA drives. But generally, there would be lesser delays. However, there are some overlaps between slower SAS and faster SATA drives.
In general, throughput is affected by the number of rpm that a drive can complete and several other factors. Normally, the drive’s throughput and other performance functions would be faster when the rpm is greater. Several SATA-based consumer drives operate at 5400 rpm and up to 7200 rpm, whereas most of the SAS-based drives operate at 7200 rpm and up to 15000 rpm.
The differences in performance would be obvious while working with large files. A 500GB file can be read and written faster on a 15000 rpm SAS drive than on a 7200 rpm SATA drive.
In both SAS and SATA, the hard drive transfer rate of data is associated with the connector type used. A SATA cable transfers the data at around 150 MB/s when compared to 300 MB/s for SATA-II and 600 MB/s for SATA-III. On the other hand, SAS cables are used to transport data at up to 600 MB/s, while current versions can transfer data at up to 1500 MB/s.
Storage Capacity
SAS gives high priority to speed over storage. Therefore, the majority of SAS drives that are available on the market have less than 500GB of hard disk space. The cost would be relatively high for drives with more than 500GB of storage capacity.
In contrast, SATA gives more importance to storage. Hence, it is simple to find a cheap SATA drive with 1TB or more capacity.
Power Consumption
SAS consumes more power when compared to SATA. Also, the signaling voltage used by a SAS drive is at least twice that of a SATA drive.
Reliability
SAS is designed for round-the-clock use in companies such as data centers. While a SATA drive can also be technically used in the same way but it would be slower and hence may fail. The MTBF of a SAS is 1.2 to 1.6 million hours of use at 45 °C, whereas a SATA drive’s MTBF is 700,000 to 1.2 million hours at 25 °C.
Basically, a hard drive can survive for more years, regardless of the activities it is used for. The statistics of all reliability and performance depend mostly on a bell curve, with the better and worst performance of some drives. When considering reliability, the brand name matters the most for both SAS and SATA. In 2013, Backblaze, a backup service, examined the reliability of 3 common hard drive brands including Hitachi, Western Digital, and Seagate. Hitachi and Western Digital proved to be the most reliable, whereas over 30% of Seagate drives failed after usage of three years.
SAS vs. SATA: Applications
Servers
To deliver web pages on a web server or host games on a game server, SAS is preferred the most because of its low failure rate and high-speed data transfer capabilities.
Personal Computing
Both SAS and SATA drives can be used for personal computing. The majority of small businesses and individuals will not employ the transmission capabilities of data every day. Often in many circumstances, sacrificing the storage of a SATA drive, which normally offers at least twice the hard disc space of a SAS drive cost fraction, is not an adequate trade-off.
SAS vs. SATA: Comparison in Tabular Form
The below-mentioned table will display the major differences between SAS and SATA.
| Attributes | SAS | SATA |
| Uses | Used in enterprises and servers | Used for storage and personal computing |
| Speed | Transfers data at the rate of 6GB/s. Transfer speed will be 2 x 6 GB/s if the SAS connection of dual-port is used | Transfers data at the rate of up to 6 GB/s |
| Speed over Capacity | SAS prioritizes speed over capacity. | SATA prioritizes capacity over speed. |
| Price | Approx. 100$ | Approx. 90$ |
| Data Cable | SAS can be up to 10m (33ft) long. The data and power are fused into one connection. | It can roughly be up to 3ft long. The data and power are split into two connections. |
| Reliability | It can be used 24/7. | It may fail after using it for a long period. |
| Advantages/Benefits | The data transfer rate is fast. Higher MTBF. Longer Cables. Higher RPM. | Inexpensive and has a large storage capacity. |
| Disadvantages | Expensive. High Power Consumption. Less Storage Capacity. | Lower MTBF. Less Suited for Servers. |
Conclusion
We hope you have gained a better understanding of SAS vs. SATA. Both SAS and SATA are unique in their own ways and they roughly do the same things. Depending on your application, you can either use SAS or SATA. Generally, SATA hard drives can be connected with SAS controllers. But SAS drives cannot be plugged into the SATA controllers.
