Problem: speckles on the surface of a black cylindrical shape

[antbin]

Hey guys,

I have been rendering a simple cylinder in dark room environment with some light sources imported to illuminate it from various directions, but the surface shows up with a lot of tiny white speckles. (see the pic below) I have tried to render with higher material sample value to get rid of them. The rendering came out batter but I can still see the speckles and now rendering takes such a long time.

Does anyone know how to get rid of them in shorter rendering time?

Assigned material
Cylinder: painted matte black (roughness 0.2_refraction 2_sample 500 )
Light sources: Area light 100W
Used environment: all black

Rendering quality
samples: 32
Ray Bounce: 10
Anti aliasing: 2
Shadow: 3
Global illumination:2
Pixel blur: 1.25

3D models are made in solidworks.

Thanks!

Antb