Normal map not working well with V-ray.

Frigus

Hello guys. I have modelled some complex and high poly scene. But my pc cant handle. It almost dying when I pan or rotate viewport. So I decided to optimize high detailed models. I am using normal map for detail on optimized models but here is the problem. When I tried to take a test render with V-ray. Light Cache destroying the normal map. Is there any solution? How can I get a perfect render with Irradiance - Light cache and normals maps

Burpee

Can you put some screenshot ? of the render and your setting ? 
Cheers! 

Frigus

I just disabled light cache not using it. Everything is fine now thanks.