Official comment
The waveform display isn't driven by a graphics engine as used in gaming, so it doesn't really take advantage of any of those features.
First and foremost, make sure your drivers are up-to-date from the manufacturer's site:
Also ensure your OS has all the latest security and system patches, and that any background tasks you don't need to have running are disabled (including things like drive indexing, Cortana / Siri).
Failing that, please file an inquiry ticket here and our rekordbox support team will be able to gather some additional information to assist you in resolving this issue.