Then Sorry to say the problem is is still exist. You can clearly see it by set priority of javaw.exe to low in Task manager.

Too bad, anyway as long as it blinks, I think I won't go further. And there was an old memory management that needed to be fixed.

I am confused beta 19 is slightily slower in perfomance than beta 1, especially in Arial view ?

I don't see what change could have produce such a performance slowdown, because the main change in the 3D part was about texture rotation. Did you try also with version 4.3?

You are right , but reducing the Refraction Index less than '1' can make easly setup metal like gold.(0.4-0.6)

Refraction Index is used only for transparent material in SunFlow. As far as I know, gold isn't transparent in solid and liquid state. In a gaseous state, I have no idea, but I don't think it's interesting for Sweet Home 3D, do you? [:))]