Modern NVMe drives typically use . The Standard driver configures each queue pair with its own interrupt vector. This allows different CPU cores to process completions simultaneously without lock contention, dramatically improving scalability on high-core-count systems. When an I/O completes, the SSD fires an MSI-X interrupt; the driver’s Interrupt Service Routine (ISR) identifies the corresponding completion queue and schedules a Deferred Procedure Call (DPC) to process completed commands.

Before understanding the driver, you must understand the hardware. NVMe is a communication protocol designed specifically for SSDs connected via the PCIe (Peripheral Component Interconnect Express) bus. Unlike older AHCI drivers (used for SATA SSDs), NVMe was built from the ground up for parallelism, low latency, and high queue depths—making it perfect for modern flash storage.