Review of the Seagate Decarbonizing Data Report

The recent Seagate "Decarbonizing Data" report highlights the growing data center sustainability and cost challenges driven by Artificial Intelligence. The analysis compares SSDs, HDDs, and LTO 9 tape storage and their embedded carbon and carbon emissions during use at the storage component level. While it correctly points out that improving sustainability and lowering costs are not mutually exclusive, the report inaccurately portrays the embedded carbon and energy consumption of LTO 9 tape storage.

For example, when comparing Storage Media and Embodied Carbon (Page 17) per unit and per TB, an 18 TB LTO 9 tape drive with one cartridge is compared to SSD and HDD. However, tape customers typically have 100-200 cartridges per drive. We adjusted the analysis to develop CO2 /TB based on 100 cartridges per drive and 7 kg of embedded CO2 per tape cartridge. In that case, the embodied carbon per TB for tape storage, including the drive and 100 tape cartridges, drops from 2.66/TB to .41/TB, roughly 60% less than 30 TB HDDs.

Similarly, for Storage Media and Power Consumption (page 19), the power for an LTO tape drive is 37 watts, and the report calculates the tape's Power Efficiency to be 1.1 Watts/TB. However, if a more representative 100 cartridges/drive is used for the Watts/TB calculation, then the Watts/TB for LTO 9 tape is .021 Watts/TB while the 30 TB HDD power efficiency is stated to be .32 W/TB. Since cartridges do not require power, with 100 cartridges/tape drive, the LTO 9 tape Watts/TB is 94% less than HDD.

In addition, new innovative solutions have emerged that seamlessly integrate tape storage into the IT infrastructure using the Amazon S3 object interfaces. These solutions reduce the technical requirements for exploiting low-cost tape storage. Some recent examples include Point Software and Systems S3-to-Tape software PoINT Archival Gateway, Grau Data XtreemStore, and the IBM Storage Deep Archive.

Hard disk drives are essential components of a data center storage infrastructure. However, tape storage is a necessary complement to disk storage and provides a more sustainable solution for inactive data. Not only does tape provide a lower carbon footprint, but it is also the lowest-cost solution.