"sparkly" clothes with iray render

U_Iuiko

I'm seeing certain clothing products have "sparkles" in shadows, as in the attached picture.  It happens with a photoreal render but not with interactive.  Is there a setting that controls this?  Or something that can be applied to the clothing?

Thanks.

 

Lord Theros

Tose are not sparkles, those are fireflies they are artifacts(noise)  that show on the render due do low light on a surface and not enough render time.