Working with MAX 2008 x64, in Win XP x64, 8 CPU, 8GB RAM, using mr rendering with Final Gather but with GI turned off to render, I noticed that my scene was rendering approximately 6 times slower using backburner on the same machine rather than rendering straight from within MAX (2 minutes vs 20 seconds per frame). The scene was pretty complicated with particles and lots of terrain geometry so I ran a test with a simple scene including a plane, some primitive shapes, no materials, but still used mental ray with final gather and mr lights. Same results, 18 seconds (via backburner on same machine) vs 3 seconds (within MAX).

I traded a single spot light with raytraced shadows for the mr lights, and still 6 times slower.

I turned off final gather, and now things render relatively in the same amount of time.

During these tests, I watched the performance tab of task manager and while rendering within MAX, I see all 8 cpu’s pegged at 100% and cranking on the frames.  During backburner rendering the CPU usage hovers around 2% and then periodically blips to 15-25% or so and then goes back down to 2%.

Anyone experience similar problems, or have any ideas on what is happening here? To double check, we have a similar workstation to mine with Vista x64 in the building, and I ran these tests there with identical results - both machines are relatively fresh installs with nothing much else running. Is this a 64 bit issue? I’ve recently converted to x64 from x32 MAX R 9, and have never had problems like this before. Any insights are appreciated. Thanks.

I am currently working with a machine with the exact same specs as yours, however I render using distributed bucket rendering instead of backburner and my renderings have never run faster. Have you considered using DBR instead of backburner? I find backburner has too many issues.

I haven’t had the opportunity to try dbr.  We are typically rendering hundreds if not thousands of frames for a project, so I don’t know if it is the best solution for us.  I’ll look into it though.  Also, I’ve found thrid party network rendering options and am going to give that a shot today.  I’ll post back with what I find.