The difference between SAS and SATA drives lies in performance and price. While the two are physically similar, they are designed for entirely different purposes.
SAS (Serial Attached SCSI) drives are able to rotate much more quickly than SATA (Serial ATA) drives. SAS drives can function up to 15,000 RPM while SATA drives typically operate around 7,200 RPM. This means that response time will be up to twice as fast with a SAS drive.
Why are they so much faster? SAS drives are built for performance. They are more durable and offer a better performance, but at a steep price. On the other hand, SATA drives are built for affordability. They are less reliable and do not offer the same level of performance, but are available at a reasonable, affordable price.
All this to say, SATA drives are not necessarily a bad choice. They are ideal for desktop computers and one-user scenarios. An SAS would be overkill on a desktop computer and simply too expensive for the average user. SAS drives are the best choice in the case of servers or data centers. Their faster performance and increased durability is essential when multiple users are depending on one device. The higher price is more than worth it in a server scenario.
In summary, SAS drives are ideal for servers while SATA drives are ideal for desktop computers.