Ok, even on a clean rebooted machine mine is going like a tortoise.

Render time 10.37

Windows XP SP2
Pentium 4     2.53Ghz
1.89Ghz 1GB RAM

I've been trying out IBL on a landscape image I've been working on a couple of weeks but it seems I would have to alter teh terrain mats and bark mats I've made in order for them to look any good under IBL.  Any tips for the kinds of things needed to make mats look good under hdri?

I've spent too long messing around trying to get HDRI working well for this scene, perhaps I need to get back to finishing it off and rendering under ordinary lighting in order to see how much better Bryce 6 is.