The phrase appears to be a promotional or descriptive tag for V-Ray 5 (a major update after V-Ray Next ) for 3D design software. Breakdown of Terms
Here is a helpful article breaking down the "5x" performance claims, the features of V-Ray Next/5, and how it integrates into your specific workflows.
To run V-Ray Next 5.x "Hot" (fast), optimize your hardware:
If you are looking for what this software offers, V-Ray 5 introduced several major workflow improvements: V-Ray 5 for Revit - Important Features Tutorial
Whether you are an Architect using Revit or a generalist using Maya, the "V-Ray Next" and "V-Ray 5" updates changed the game differently for each platform.