I posted the question in the autodesk community, I don't know how to insert image in this forum so I just copy the link of my post in the autodesk community here below, appreciate the one more click:)
http://forums.autodesk.com/t5/3ds-max-3ds-max-design-general/guys-how-to-make-vray-renderoutput-less-grainy/td-p/5783033
and here you can see in the attachment the materials that are black and have glossy reflection have tiny white noise on them and the glass cover of the design is the worse, as the highlight along the side is not continue and the edge has clear alias
I would be greatly appreciated if you can help me boost up the image quality without setting adaptive max subdivide to 100+ and min shade to 400+, I tried, and it doesn't work unfortunately