HDD
HDD are Disk objects of type HDD.
Characteristics
| Name | Unit | Default value | Description | Example |
|---|---|---|---|---|
| units | None | 1 | HDD quantity | 2 |
| usage | None | See Usage | See usage | .. |
| type | None | HDD | "HDD" | HDD |
| capacity | Go | None | Capacity of a HDD disk | 1000 |
Embedded impacts
Impacts criteria
| Criteria | Implemented | Source |
|---|---|---|
| gwp | yes | Green Cloud Computing, 2021 |
| adp | yes | Green Cloud Computing, 2021 |
| pe | yes | Green Cloud Computing, 2021 |
| gwppb | no | |
| gwppf | no | |
| gwpplu | no | |
| ir | no | |
| lu | no | |
| odp | no | |
| pm | no | |
| pocp | no | |
| wu | no | |
| mips | no | |
| adpe | no | |
| adpf | no | |
| ap | no | |
| ctue | no | |
| ctuh_c | no | |
| ctuh_nc | no | |
| epf | no | |
| epm | no | |
| ept | no |
Impact factors
The HDD disk manufacturing impact is considered as a constant.
| Constant | Unit | Value |
|---|---|---|
| \(\text{HDD}_{\text{embedded}}^{\text{gwp}}\) | kgCO2eq | 31.11 |
| \(\text{HDD}_{\text{embedded}}^{\text{adp}}\) | kgSbeq | 2.50E-04 |
| \(\text{HDD}_{\text{embedded}}^{\text{pe}}\) | MJ | 276.00 |
Info
If there are more than 1 HDD we multiply \(\text{HDD}_\text{embedded}^\text{criteria}\) by the number of HDD given in units.
Usage impact
Only power consumption is implemented.
When part of a server or a cloud instance, each drive is assumed to draw a constant 6.4 W (min 5.4 W, max 9.4 W), independently of the workload. HDD power is close to constant with load since the platters spin whether the drive is busy or not.
Sources: LBNL, 2024 United States Data Center Energy Usage Report (6.4 W per HDD in 2025), Seagate Exos X20 review (5.4 W idle, 9.4 W random read), cloud-carbon-exporter (7.5 W per HDD).
Power is modelled per drive rather than per TB because it does not grow with capacity: Toshiba's enterprise HDDs went from 6 TB at 11.3 W in 2013 to 16 TB at 7.7 W in 2019 (Toshiba, 1 Petabyte of Online Storage white paper).