Problem with slow rendering - Sketchup 2018 + Vray 3.6

Without seeing the model or final rendering it’s hard to answer what’s slowing things down. See similar post here. Speed is primarily affected by 3 things: 1. Computer (yours seems like it should do ok), 2. Output settings (size and quality) and 3. Model content (materials like reflection and transparency, high amounts of vegetation, etc)