How to make IRay use GPU rather than CPU?

I'm doing a test render of genesis. I have a GTX 1070 selected with optix enabled but it still only uses the CPU. If I select just the GPU and no CPU then nothing gets rendered. Here's the log file:
2016-29-07 16:29:55.720 Iray INFO - module:category(IRAY:RENDER): 1.0 IRAY rend info : Updating geometry.
2016-29-07 16:29:55.720 Iray INFO - module:category(IRAY:RENDER): 1.0 IRAY rend info : Using OptiX Prime ray tracing.
2016-29-07 16:29:55.767 Iray INFO - module:category(IRAY:RENDER): 1.0 IRAY rend info : Geometry import (1 object with 151k triangles, 1 instance yielding 151k triangles) took 0.034193
2016-29-07 16:29:55.767 Iray INFO - module:category(IRAY:RENDER): 1.0 IRAY rend info : Updating materials.
2016-29-07 16:29:55.773 Iray INFO - module:category(MATCNV:RENDER): 1.0 MATCNV rend info : found 137 textures, 0 lambdas (0 unique)
2016-29-07 16:29:55.774 Iray INFO - module:category(IRAY:RENDER): 1.0 IRAY rend info : Updating environment.
2016-29-07 16:29:55.780 Iray INFO - module:category(IRAY:RENDER): 1.0 IRAY rend info : Updating lights.
2016-29-07 16:29:55.780 Iray INFO - module:category(IRAY:RENDER): 1.0 IRAY rend info : Updating object flags.
2016-29-07 16:29:55.780 Iray INFO - module:category(IRAY:RENDER): 1.0 IRAY rend info : Updating caustic portals.
2016-29-07 16:29:55.780 Iray INFO - module:category(IRAY:RENDER): 1.0 IRAY rend info : Updating decals.
2016-29-07 16:29:55.782 Iray INFO - module:category(IRAY:RENDER): 1.0 IRAY rend info : Using batch scheduling, architectural sampler disabled, caustic sampler disabled
2016-29-07 16:29:55.782 Iray INFO - module:category(IRAY:RENDER): 1.0 IRAY rend info : Initializing local rendering.
2016-29-07 16:29:55.783 Iray INFO - module:category(IRAY:RENDER): 1.0 IRAY rend info : CPU: using 4 cores for rendering
2016-29-07 16:29:55.783 Iray INFO - module:category(IRAY:RENDER): 1.0 IRAY rend info : Rendering with 1 device(s):
2016-29-07 16:29:55.783 Iray INFO - module:category(IRAY:RENDER): 1.0 IRAY rend info : CPU
2016-29-07 16:29:55.783 Iray INFO - module:category(IRAY:RENDER): 1.0 IRAY rend info : Rendering...
2016-29-07 16:29:56.884 Iray INFO - module:category(IRAY:RENDER): 1.3 IRAY rend info : Initializing light hierarchy.
2016-29-07 16:29:57.050 Iray INFO - module:category(IRAY:RENDER): 1.2 IRAY rend info : CPU: Scene processed in 1.267s
2016-29-07 16:29:57.051 Iray INFO - module:category(IRAY:RENDER): 1.2 IRAY rend info : CPU: Allocated 7 MB for frame buffer
I've attached a screenshot of my settings, how do I get it to use the GPU? The GPU has plenty of free memory so that should not be the issue.
I read this thread but did not find a solution: http://www.daz3d.com/forums/discussion/74758/daz-iray-not-using-gpu-to-render
Thanks for your help


Comments
The current release version (4.9.2.70) doesn't support Pascal GPU's. The current Beta version (4.9.3.128) will, but it is still Beta software.
Same answer as in the thread you referenced.