SAS vs. SATA Drives


Nowadays, knowledge of Hard Disk Drives become increasingly important as the requirements of capacity and performance of storage are growing exponentially in huge enterprises or even small and medium business environments. People that talk about the needs of storage would also come out with a question – SAS or SATA, what kind of drive should I use? – and most of people would prefer to purchase/use the “better” one, but actually a “suitable” drive should be considered first for different environments. Here, we will describe the benefits of each and suggest a proper environment in which to apply them.

SATA Overview

SATA, Serial Advanced Technology Attachment, drive interfaces are usually made for high capacity with nice performance upon 7200 RPM (Revolutions Per Minutes) for HDD’s, or SSD’s with low DWPD (Drive Writes Per Day) value, and are suitable to be used in environments like Video Editing, Surveillance, Media Streaming, and any file archiving place. As the MTBF (Mean Time Between Failure) of SATA drives are generally less than SAS, an IT guy would prefer to create a RAID Pool (or any technique that supports tolerance of drive failure) with a higher tolerance RAID type, RAID6 or even RAID10, though sacrificing a few more capacities, preventing the situation of service interruption because of whole failure of RAID. This is still acceptable due to the Cost Performance of a SATA drive being affordable.

SAS Overview

SAS, Serial Attached SCSI (pronounced “scuzzy”), drives are made for extreme high performance and low response time upon 10K or 15K RPM HDD’s, or SSD’s with high DWPD value, which are suitable to be used in environments like VDI (Virtual Desktop Infrastructure), SQL Database, and any high intensive I/O architecture you can imagine. MTBF, on the contrary, is much better than SATA drives, and usually using a RAID type with less tolerance of drive failure would be recommended for achieving the goal of high performance or low latency, especially for those applications that require latency to be lower than 2ms while delivering hundred thousands of IOPS. The cost per GB for SAS drive are quite high though.

Final Thoughts

SATA and SAS drives have their pros and cons and people should be able to choose the right one to meet the requirements of each project respectively; selecting proper enclosure to contain those drives is also important for accomplishing the total solution via RAID technology. QSAN provides products that meet the purpose of the above requirements over different platforms. Visit QSAN for more details to solve your hassles.