Memories, memory arrays, and methods for selectively providing electrical power to memory sections of a memory array are disclosed. A memory array can be operated by decoupling row decoder circuitry from receiving electrical power while the memory array is not being accessed. Portions of the memory array to be accessed are determined from external memory addresses and the row decoder for the portions of the memory array to be accessed are selectively provided with electrical power. The section of memory is then accessed. One such array includes memory section voltage supply rails having decoder circuits coupled to receive electrical power, and further includes memory section power control logic. The control logic selectively couples the memory section voltage supply rail to a primary voltage supply to provide electrical power to the memory section voltage supply rail in response to being selected based on memory addresses.