The Houdini 11 (11.0.489) scene view, 3D viewport, is extremely slow in the OS X version running on 10.5.8.

Flat and smooth shading bring it to a standstill. Wireframe is still fast. V10 is very fast and smooth is all modes.

To duplicate:
1. Download and install v11
2. Open test file which contains one isosurface node.
3. Try tumbling the view. V11 will not track interactively with default settings.

Opening both v10 and v11 with the test file I notice v11 has much brighter highlights, which may be a clue.

Does anyone else have this problem?

I don't see this problem in the windows 64 bit version.

I've tried 11.0.469 and several daily builds since then
2009 Mac Pro 2.66 GHz Quad-Core Intel Xeon
OS X 10.5.8
NVIDIA GeForce GT 120

OpenGL on the Mac has greatly improved in performance since 10.5.8. I highly recommend updating to 10.6.4.

Houdini 11 uses smooth-shaded per-pixel lighting (with GLSL shaders) while Houdini 10 uses fixed-function vertex lighting. You can turn off Material Shaders in the Effects tab of the Display Options if upgrading to 10.6.4 is not an option.

Edit: The performance disparity between drivers on Win64 and Mac OSX shows just how slow Apple's OpenGL drivers are.

twod: Thank you. Turning off the material shaders in the effects tab did the trick and returned performance to v10 speed. I have ordered the upgrade to 10.6.4.

There is a “Graphics Update” which should appear in your software update list when you install 10.6.4. Make sure you install that after installing 10.6.4; it improves performance substantially.