Hi Alex!
Based on your system specs, you should have decent performance for video editing, so the lag issues you are experiencing are not normal.
It’s possible that the cause of the lag is that your system is processing the original video file at 4K resolution in real time, which can be very demanding for any hardware, even for a high-end workstation. That’s why setting the timeline resolution to a quarter of its original size helps ease the load and improve performance.
One possible solution is to use proxies, which are low-resolution versions of your original video files, but keep the same length and aspect ratios. These proxies are used in editing instead of the original video files, which significantly reduces the processing load on your system.
Smart caching can also help improve performance by caching parts of the timeline that have already been processed for smoother playback in future playbacks. However, it may not be enough to improve real-time editing performance.
I recommend that you try working with proxies to see if that improves editing performance. If you are still experiencing performance issues, you can also try closing other applications that are consuming resources in the background while editing as sometimes I’ve gone from editing to noticing that it’s heavy davinci and closed everything out and it worked… or consider updating your graphics card drivers or reinstalling your video editing software.
try those tips and if you still have problems let us know so we can go deeper into your problem and solve it!
Steven.