According to one embodiment, a memory system includes a nonvolatile memory including a plurality of memory chips and a controller. The controller acquires a first command from a first queue, transmits the acquired first command to a first memory chip, thereafter acquires a second command from a second queue, and transmit the acquired second command to a second memory chip when a first command processing speed based on a time until execution of a command using the first memory chip is completed after transmission of the command to the first memory chip is started is lower than a second command processing speed based on a time until execution of a command using the second memory chip is completed after transmission of the command to the second memory chip is started.