Although it has more memory than the minimum recommended environment, there are times when the operation is slow due to lack of specs. Editing in 4K. I tried all the optimized media, render cache, timeline resolution, etc. Is there anything you can think of as a problem with hardware specs?
Make sure that all installed memory can be used as main memory.
Some PCs share graphics memory with main memory.
DaVinci Resolve should be able to use 4GB of VRAM at HD resolutions and 8GB of VRAM at 4K resolutions.
Also, the minimum recommended environment for the main memory of DaVinci Resolve is 16GB for Windows.
For this reason, even if the PC has 16GB of memory, if the graphics memory is shared with the main memory, it will not meet the recommended playback environment.
You may be able to expect some improvement depending on the resolution of the timeline, but please consider increasing the memory for a fundamental improvement.