Abstract: A die-aware scheduler that has a hierarchical queue is suitable for use in data storage systems. The hierarchical queue includes a priority queue, a die queue, a write queue and a power token queue, and may also include an admission queue. The die queue, the write queue and the power token queue have a width and lanes corresponding to dies in solid-state storage. The hierarchy of queues has dynamic adjustability of a ratio relating to handling queue items in the hierarchy of queues, to optimize latency and throughput.