How to Reduce Noise

And also bump up the global subdivs multiplier at DMC sampler setting...

This is good and works, but can drive up render times too much because it multiplies the subdivs of everything even things you don't want, you are usually better off tuning individual subdivs if you can.

Ya i know that. But it's an easy way to reduce noise. Working on sub division on every materials is not easy for everyone.

And also bump up the global subdivs multiplier at DMC sampler setting...

This is good and works, but can drive up render times too much because it multiplies the subdivs of everything even things you don't want, you are usually better off tuning individual subdivs if you can.

thousand thanks to everyone for posting your nice comments on it...and yeah definately will try to make all these settings implement.

you ain`t got enough light, either use a light dome with a map to increase the total amount of light in the scene , or use global lights( lights that are not purposed but to lighten up the scene) these noises are coming from that, onr quick note , never use a light cache amount under 2000 for final results ,

noise threshold value .005 for the final render. And also bump up the global subdivs multiplier at DMC sampler setting...

Try turning the irradiance map preset down to low, that seems backwards but a higher preset increases the resolution of the IR map and can make noise more defined. Also, try increasing the interp samples, and the light cache subdivisions a bit, shouldn't affect your render times too much. Also, lights in your scene can have a big impact on noise, try increasing the individual subdiv parameters of your lights, be careful with that though because that will drive render time up quickly.