A solid state drive (SSD) device includes a plurality of nonvolatile memory devices and a SSD controller. The SSD controller is configured to allocate a resource of the SSD device based on workloads of a plurality of streams and to control operations of the nonvolatile memory devices. Accordingly, the resources of the SSD device are adjusted according to the workloads of the streams so that the SSD device may support a multi stream system with reducing performance deterioration.