This post is a part of a six-part series from the white paper "The Measure of an Enclosure-Five Factors to Consider When Choosing External Data Storage". Can't wait to read the whole paper? You don't have to! Read it right here. The paper includes a glossary, charts and illustrations to help explain further.

DATA TRANSFER RATINGS ARE A “BEST GUESS”

Throughput ratings are theoretical and do not take into account the overhead of the information transfer protocol being used, among other factors. The transfer protocol is the code that allows data transfers to take place, and it must be sent along with the data being transferred, which decreases how much of your data can be sent at a time. For example, the fastest SSDs measured today top out around 550 MB/s1, or 4.4 Gbps, even though they theoretically could max out at the 6 Gbps throughput of their SATA 3 interface. This mismatch between theoretical throughput and real-world performance is due to factors such as this.

While each throughput rating for each interface is fairly accurate in comparison to other interfaces, you should always keep in mind that they are optimistic approximations of the performance you will get in a best- case scenario.

This post is an excerpt from the white paper "The Measure of an Enclosure-Five Factors to Consider When Choosing External Data Storage". Read the complete paper for technology choices and five factors to think about when making a decision on what external drive will work best for your needs.