Thanks Robert,
Once again, I kinda thought that was the way it is. I know about some features (bump maps, etc.) don't work without multi-pass. As I get deeper into using this wonderful software, I want my understanding to hopefully grow as well. So I thought I'd ask.
Multi-pass 1, small resolution= trial renders>short render times,
Multipass 16?, whatever resolution = final product>much longer render time (much better-product)
EDIT: Thanks again to you , Sir Rodney. You posted as I was typing. I'd read that tech manual more often if I could get my eyes to quit glazing over about halfway down the page.