Dome vs Plane Light Noise Problem

[hk]

Hi everyone.

 

I've been experiencing this issue for a long time, like 7 years long. I had enough so i need your help.

 

I want to use HDRI lighting for interiors so way to go is VrayDome i think. But when i use VrayDome i can't even have a low quality render. It's that bad. Why is that?

 

Below you can see two examples.

 

Both test are on same settings

GI is of

Use local subdivs is unticked

Window has no glass

 

One is with Vray Plane Light behind the window, the other has a Dome Light "without" a HDRI

 

I need your help,

 

Thanks.