Carbon Footprint of Storage – HDD vs. SSD

Methodology of the Cloud Carbon Footprint tool

HDD: Watt Hours / Terabyte: 0.65
SSD: Watt Hours / Terabyte: 1.2

Source: https://www.cloudcarbonfootprint.org/docs/methodology/#storage

HotCarbon 2022: The Dirty Secret of SSDs: Embodied Carbon

Tannu and Nair calculate that manufacturing a 1 terabyte SSD emits the equivalent of 320 kg of carbon dioxide. By comparison, a similar HDD emits just 40 kg.

Paper: https://hotcarbon.org/assets/2022/pdf/hotcarbon22-tannu.pdf
Video: https://youtu.be/-0tzoSEL8iA

ACM: https://dl.acm.org/doi/abs/10.1145/3630614.3630616

HotCarbon 2024: A Call for Research on Storage Emissions

@McAllister.etal.2024.CallResearchStorage

SSD rack vs. HDD rack:

~4× the operational emissions per TB
~10× the embodied emissions per TB

mcallister.etal.2024.callresearchstorage (pg. 3)

SSD racks emit approximately 10× the embodied emissions per TB as that of HDD storage racks. The storage devices themselves dominate embodied emissions, accounting for 81% and 55% of emissions in SSD and HDD racks, respectively.

mcallister.etal.2024.callresearchstorage (pg. 1)

Cloud data storage today has two media options: hard-disk drives (HDD), for storing large amounts of data, and solid-state drives, for low-latency data access. SSDs are about 2-4x more expensive per bit than HDDs [1, 4]. For carbon, the difference is even more pronounced — SSDs require 3-10x more embodied emissions per bit [70, 128] and more power per bit (Sec. 3.1).

mcallister.etal.2024.callresearchstorage (image) (pg. 3)

Table 2: Operational emission breakdown for Azure rack types.

mcallister.etal.2024.callresearchstorage (image) (pg. 3)

Table 3: Embodied emission breakdown for Azure racks.