Big Picture: Early SSDs were advertised as being more energy efficient than their spinning HDD counterparts. As the speed increased with each successive generation, so did the power and heat requirements. Some high-end Gen 4 drives are already benefiting significantly from dedicated cooling, and we’ll likely see this trend become more prevalent with future SSDs.
Thermal management will become more important than ever as PCIe 5 devices begin to hit the market.
“As the speed continues to increase with each new generation, our challenge will continue to be heat management,” Jin said.
As a general rule, Jin points out that each additional GB/s of speed provided by an SSD requires about one additional watt of power. “We’re trying to stick to roughly the same power band as a 7GB/s SSD as we push the speed up to 14GB/s while making a lot of other changes,” Jin added.
One way to reduce power consumption is to reduce the number of NAND channels used by the SSD.
“From a practical standpoint, you no longer need eight lanes to saturate a PCIe Gen4 or even Gen5 interface. You can potentially saturate the host interface with four NAND channels, and reducing the number of internal channels reduces the overall power of the SSD, typically by 20 to 30 percent,” Jin said.
Another method is to use a smaller process node, for example when going from 16 nm to 7 nm. Fison notes that small process units can operate at higher frequencies at lower voltages. Drives on smaller nodes also require less power to switch transistors, further reducing power consumption and ultimately heat generation.
Despite the improvements, Jean said he expects to see passive heatsinks with Gen 5 devices. “Eventually, we will also need a fan that will force air directly onto the heatsink,” he added.
While not ideal, passive/active cooling is certainly doable for most desktop configurations. Laptops and small desktops, however, can be a big problem due to their extremely limited footprint.