The answer can actually vary depending on multiple variables such as system type, applications, and the type of specific memory installed. For these reasons, we do not advertise specific power usage of any of our memory. As a rule of thumb however, you want to allocate around 3 watts of power per every 8GB of DDR3 or DDR4 memory.
High performance memory such as Ballistix parts can draw more power, especially if you overclock the voltage beyond XMP settings. Registered (RDIMM) parts with more DRAM components draw additional power as well. Conversely load reduced memory (LRDIMMs) for a server can use a little less power per GB because those parts work with a lower data load to allow higher capacities and lower power needs.
If you are building your own computer and you want to know how large of a power supply you should purchase, it is a good idea to use one of the free “power supply calculators” you can find online, or consult your motherboard and/or system manufacture for guidance.