Why does The Last of Us Part I drop frames with Crucial DDR5 5600?

It was ironic that with top-tier memory, I still experienced sudden frame rate plunges when facing hordes of infected. I first tried manually setting CPU affinity in Task Manager, but the game crashed directly to the desktop. I then used the GamePP Process Priority Manager to set the game to Real-time priority. RTSS showed the frame time curve stabilized from a volatile 12-40ms to a consistent 8-11ms, while HWMonitor recorded stable temps at 56-62℃.