The V-Ray Benchmark results page provides an extensive list of hardware combinations tested with V-Ray.
Please make sure that your system fulfills these requirements before installing V-Ray. Note that V-Ray is only supported for 64-bit operating systems. Intel® or AMD® 64-bit processor with SSE 4.2 support 8 GB RAM and 8 GB swap minimum Minimum System Requirements Processor RAM GPU NVIDIA® GPU with compute capability 5.2 
with NVIDIA Display driver 436.30 or higher. Non-supported GPU hardware fallbacks to CPU renderingUnreal Engine Editor version 4.25.4; 4.26.2; 4.27.2 Supported Operating Systems Windows® 7 SP1 64-bit, Windows® 8 & 8.1 x64, Windows® 10
Please make sure you have the appropriate version of Visual Studio for project packaging in Unreal.Unreal Engine Editor version Minimum Visual Studio version 4.25.4 VS 2017 4.26.2 VS 2017 4.27.2 VS 2017