rtpt wrote:toxie, i agree that iray is a handy/candy tool for 3d artists but the performance of iray on a single monster host or on a cluster is a
magnitude behind any home-optimized/hand-tuned systems. so we mostly avoid using iray & co in time critical projects.
It depends on what you want to do, i think. If you want to interactively walk through a large dataset including proper lighting and detailed/real-life materials (e.g. no hacks and approximations), then iray actually scales extremely well on a cluster.
But if you're doing offline rendering and can live with approximations and tweaking a couple of knobs for each shot, then iray can not compete with all of the existing renderers out there. And this was also not our goal when starting this project.
Note though that there is the "iray interactive" renderer available in addition to iray photoreal since a while, and this one cuts some corners/uses approximations, so maybe you could give that one a try (ships with most plugins and integrations of iray)?