Particles and smoke simulations will add time to a render on any PC.
A likely cause is your hardware, Eevee uses only GPU rendering, utilizing the CPU to prepare models for the GPU to render.
What are your PC specs? (GPU (vram), CPU, Mem)
Is your OS and device drivers up to date? (GPU drivers specifically)
also,
How dense is the scene? (Number of objects, tris)
What Blender version are you using?
