Most people know by now about the difference between hard disk drives (HDD) and solid-state drives (SSD). A classic HDD uses magnetic metal plates and small mechanical devices to read data while an SSD utilizes integrated circuits in the form of flash memory to store data – no moving parts, no magnetic plates. Generally speaking, SSDs are far superior – data transfer rates are higher, latency is lower, and are physically more robust than their mechanical counterparts.
And of course, the cost of an SSD tends to be much higher – but costs have lowered significantly in recent years, to the point where the average user really should have a good reason to NOT use an SSD. They’ve more or less become standard.
But what many people don’t yet know are the differences between SSDs themselves – chiefly, the difference between SATA and SAS (Serial Attached Storage) solid-state drives. While the difference between SATA and SAS may not mean much for the average computer user, it can make a world of difference on the infrastructure-side.
Without getting overly technical, SAS drives use a different internal configuration to provide a platform with higher transfer rates and reliability over their SATA counterparts, with even some allowance for data correction and dual-port failover. What this means for the business is better read/write performance with a lower margin of error and data corruption.
The below graphic will be mildly obtuse to non-technical readers, but you can still get a sense for the advantages of SAS technology, especially where timing is considered:
SAS drives really shine in situations where quick read/write times are paramount with a critical need for storing data correctly the first time. Some examples of these I’ve seen in my own IT career are with market trading and pharmaceutical server software – lots of entries and queries within a very short amount of time. Lower latency by even just a few milliseconds can make a world of difference when all is said and done at the end of the workday.
The main drawback of SAS drives are the expense – the last time I checked, SAS SSDs tend to cost anywhere from 75% to 200% more in comparison to their SATA-type counterparts of the same storage size. Especially in the instance of network storage running 20+ drives, the cost adds up quickly. For this reason, it can be advantageous to stick with SATA where high-speed data transfer and reliability aren’t as big of a priority – long-term archival storage is a good example of this.
I’ve also heard rumors that SAS SSDs taste better. Am I the only one who likes to dunk an SSD in my morning coffee? Surely, I’m not alone in this.
Know the differences in everyday vital enterprise technologies – it makes the difference between a “good” IT professional and an “excellent” IT professional!
Categories: The IT Philosopher
Austin Thomé - Cloud & DevOps Engineer 