The 390605-B21 is a dual‑core AMD Opteron 865 processor designed for HP systems, featuring a 1.8 GHz clock speed and 2 MB of L2 cache. It conforms to the Socket 940 platform, ensuring compatibility with servers and workstations that support this socket type. As an AMD Opteron model, the processor delivers the multi‑threaded performance expected from a dual‑core architecture, suitable for demanding workloads in enterprise environments. The part number 390605‑B21 identifies this specific unit for ordering and inventory purposes, helping customers match it precisely to compatible HP hardware configurations.