The Dirty Secret of SSDs: Embodied Carbon
Swamit Tannu, Prashant J. Nair
TL;DR
This paper investigates the embodied carbon costs of SSDs relative to HDDs in data storage, arguing that memory fabrication is a major contributor to overall CO$_2$e and that SSDs exhibit substantially higher embodied emissions per capacity, quantified by a Storage Embodied Factor of $0.16$ kg CO$_2$e/GB. It synthesizes LCAs from $94$ SSD LCAs and $24$ HDD LCAs to show a near-linear increase of embodied carbon with SSD capacity, and it highlights that technology scaling and fossil-fuel electricity in fabrication amplify emissions. The authors propose a framework of strategies—selecting appropriate storage media, extending SSD lifetimes via wear leveling and data-placement choices (e.g., SLC vs MLC, ZNS), recycling/reusing flash, efficient ECC, and leveraging cloud elasticity—to curb embodied carbon in storage systems. The work emphasizes that infrastructure and data-management decisions, including cloud deployment patterns, can meaningfully reduce embodied CO$_2$e and guide sustainable design for future data centers and devices.
Abstract
Scalable Solid-State Drives (SSDs) have ushered in a transformative era in data storage and accessibility, spanning both data centers and portable devices. However, the strides made in scaling this technology can bear significant environmental consequences. On a global scale, a notable portion of semiconductor manufacturing relies on electricity derived from coal and natural gas sources. A striking example of this is the manufacturing process for a single Gigabyte of Flash memory, which emits approximately 0.16 Kg of CO2 - a considerable fraction of the total carbon emissions attributed to the system. Remarkably, the manufacturing of storage devices alone contributed to an estimated 20 million metric tonnes of CO2 emissions in the year 2021. In light of these environmental concerns, this paper delves into an analysis of the sustainability trade-offs inherent in Solid-State Drives (SSDs) when compared to traditional Hard Disk Drives (HDDs). Moreover, this study proposes methodologies to gauge the embodied carbon costs associated with storage systems effectively. The research encompasses four key strategies to enhance the sustainability of storage systems. In summation, this paper critically addresses the embodied carbon issues associated with SSDs, comparing them with HDDs, and proposes a comprehensive framework of strategies to enhance the sustainability of storage systems.