A new study alleges that while SSDs are more energy efficient, they cause significantly higher carbon emissions than HDDs. however, different usage scenarios may change this.
Researchers at the University of Wisconsin-Madison and the University of British Columbia recently published a study claiming that SSDs may cause twice the carbon emissions of hard disk drives. The study analyzed the carbon impact of different devices and components over their life cycle.
The researchers acknowledge that operating SSDs consumes less energy than HDDs, but claim that manufacturing SSDs leads to much higher emissions. Assuming that the manufacturing process still relies primarily on fossil fuels, most of the carbon emissions from SSDs occur before people start using them.
The study concluded that SSD emissions are highest in systems that use them, accounting for 38 percent of total PC emissions. By comparison, hard drives may account for 9% of system emissions, GPUs for 11%, CPUs for 4%, motherboards for 17%, memory for 9%, PSUs for 4% and cases for 6%. This percentage is predicated on a 512GB SSD, but interestingly, the cost of carbon in the manufacturing process for SSDs is said to increase linearly with increasing capacity.
Comparing the theoretical emissions of the two storage devices from manufacturing to end-of-life, the study concluded that HDDs use more energy than SSDs over a five- to 10-year period, but less energy than manufacturing SSDs. The researchers assumed 20 percent active cycles and 80 percent idle cycles over the life cycle of both storage media. Under similar workloads, the speed of SSDs may result in fewer active cycles, increasing their energy efficiency lead over HDDs.
The study suggests ways to reduce storage emissions. Designing SSDs with longer lifetimes is an obvious solution, as it can result in less energy consumption for use. Recycling and reusing flash memory also helps the environment. In addition, SSDs are not always the best storage for every situation. Hard drives are still cheap per gigabyte, which is why it makes sense for users and companies to adopt them for cold storage and reserve SSDs for frequently used files.
