A memory subsystem is enabled with a write pattern command. The write pattern command can have a different command encoding from other write commands. The write pattern command triggers a dynamic random access memory (DRAM) device to write a data pattern that is internally generated, instead of a bit pattern on the data signal lines of the data bus. The internally generated data pattern can be read from a register, such as a mode register. In response to a write pattern command, the DRAM device provides the write pattern data from the register to the memory array to write. Thus, the memory controller does not need to send the data to the memory device.