Davinci resolve render แล วไม ม เส ยง

I'm currently encountering a persistent issue while rendering a feature film on DaVinci Resolve 18.6, utilizing a robust setup comprising an AMD Ryzen 9 5950X processor, 64GB RAM, and an NVIDIA GeForce 3080TI 12GB GPU running on Windows 11 Pro 22H2 with GeForce Game Ready Driver 537.42.

The film's timeline primarily consists of footage shot in RED RAW 4K-6K, with a few DJI ProRes 4444 clips. Initially, the rendering speed is normal at around 15-17 FPS. However, it drastically slows down to an unworkable 0-0.5 FPS when the GPU memory is nearly full (11.2GB/12GB) and RAM usage approaches its limit (40.7/64GB). This happens particularly after rendering light masking fusion clips in the timeline.

A similar issue occurred in the past with a previous GPU, the GeForce 3070 8GB, while attempting to render a shorter 12-minute film comprised entirely of RED RAW 6K clips with denoise nodes.

Interestingly, when I attempted to render the same content on MacBooks, including an M1 with 8GB and an M1 Pro with 16GB, the rendering proceeded at a normal and satisfactory speed, indicating a potential anomaly with my PC setup.

I would greatly appreciate any insights, advice, or troubleshooting steps to resolve this issue and optimize my rendering performance on DaVinci Resolve 18.6.