Part number 445981-B21 is an HP‑branded AMD Opteron 2356 processor designed for the ProLiant DL165 G5 server. The quad‑core CPU operates at 2.30 GHz and includes a 2 MB L3 cache, delivering the processing power required for typical enterprise workloads and virtualization tasks. Engineered to meet HP’s quality standards, this processor provides a direct replacement for original equipment, ensuring compatibility with the server’s chipset and firmware. Installing the Opteron 2356 restores full system performance and reliability for data‑center, compute‑intensive, or mixed‑use applications.