If you're using Poser 11 there are some things you can do to tone down the noise in your renders."Filter Glossy, Clamp Direct and Clamp Indirect". Turn up the filter and turn down the clamp. If you turn clamp down too far (less than 1) it will darken the whole scene.

These settings aren't as effective as adaptive sampling and OiDN in P12 but the can help a lot.