The hard drive refuses to disappear into the data center. And studies like the one just published by Scality prove that perhaps HDD still has a few years to live. As this company specialized in storage assures, solid-state drives, which have gained a reputation for their speed of access and have become popular due to the price drop in recent years, would not necessarily be the more energy efficient environment.
Thus, as the multinational seems to demonstrate, depending on the workloads and the capacities of the units, a new study shows that hard drives can offer 19% to 94% higher energy density per unit compared to SSDs.
Unlike SSDs, hard drives have many moving parts, such as platters or read arms, so the fact that they are less power efficient may seem counterintuitive.
However, the results that Scality arrives at seem to show the exact opposite. The study reveals in this sense that hard drives are more efficient when compared to high-density QLC SSDs. Scality used to demonstrate the unity 30.72TB Micron 6500 ION QLC SSDwhich faced with the hard drive Seagate Exos X22 22TB 7,200RPM for this comparison.
Looking at the power density metric, which we measure in TB/Watt, the hard drive had a 19% advantage in reading and 94% in writing. At idle, on the other hand, the hard drive consumed 14% more energy than the SSD.
However, the hard drive had 37% and 68% lower power consumption during active read and write operations, both in regular operations, and according to the company, also when running heavy workloads. Of course for this experiment the performance offered by both drives was not measured (higher in the case of the SSD) and Squality also admits that power consumption may improve on these drives in the future.
In fact, the company also states in this study that “power consumption is not today a primary criteria on which to base the decision of SSD vs. HD”. It all depends on the workload. For example, SSDs remain the best performance choice for latency-sensitive, read-intensive workloads. Meanwhile, hard drives remain the preferred medium for unstructured data workloads.