Most unanticipated FPS drops on OSX are due to the driver dropping off the fast path, or in the worst case, dropping to software. Some GPUs will have no problem with a given scenario while others will stutter. Mobile GPUs seem to be most likely to suffer performance issues, while discrete GPUs are much more robust (but unfortunately are used in very few Apple products).

In general, it's pretty hard to determine why a performance drop happens. Sometimes it's a simple thing like it not liking how a particular GLSL shader is formed, but other times it's nearly impossible to determine what the issue is. Other platforms have much better performance consistency.

Yep - the much heralded Mari on OsX, with it's GL4 viewport shown at WWDC a few years back at the unveiling of the nMP, suffers from dropping to the clunky software path too, and, the viewport stutters as well. Was quite surprised tbh.

So for the future, Apple seems like it will drop support for OpenGL and they also look like they are not going to support Vulkan either. If Metal is the only API Apple will be supporting then what would that mean for Houdini users on Apple platform ?

tinyparticle
So for the future, Apple seems like it will drop support for OpenGL and they also look like they are not going to support Vulkan either. If Metal is the only API Apple will be supporting then what would that mean for Houdini users on Apple platform ?

I'm also curious what's going to happen here. I've reduced my Houdini on OSX usage to a minimum ever since antialiasing got turned off for my ATI card due to an Apple bug. Ghosted wireframe became useless to me. Also, the startup times used to be much quicker and is now much slower, and strangely even slower running from the terminal.

Any insights are much appreciated.

Andy

tinyparticle
So for the future, Apple seems like it will drop support for OpenGL and they also look like they are not going to support Vulkan either. If Metal is the only API Apple will be supporting then what would that mean for Houdini users on Apple platform ?

I have just as much news about Apple's plans as everyone else - none Apple plays their cards very close to their chest.

However, I'd be surprised if they dropped OpenGL, especially while Metal is not an effective replacement. They'd effectively kill all non-mobile gaming and high-end apps on OSX. Perhaps once Metal does gain Tess and Geom shader support, they might think about dropping GL, but I think we're safe for now. If Metal also gained a GLSL shader cross-compiler it'd be much easier to port to (we have over 1000 GLSL shader files).

Vulkan 1.0 is missing Transform Feedback so Houdini can't be ported to it right now anyway. The Vulkan team is aware of this and it'll hopefully make its debut in the next cut of Vulkan.

Also, the startup times used to be much quicker and is now much slower, and strangely even slower running from the terminal.

That could be something on our side. Hard to tell because I have a very old Mac Pro, and Houdini has always taken forever to start up on that.

As for the AMD AA bug, I'll ask them about that again. Haven't heard anything from them in several months.

twod
That could be something on our side. Hard to tell because I have a very old Mac Pro, and Houdini has always taken forever to start up on that.

Yup those OsX startup times are starting to lag. ~18sec vs 3sec, same macmini i7 @ 2Ghz machine booted in OsX vs Ubuntu.

If someone else can chase this it would be great. Little time for non-critical things currently. Cheers.

Not sure if this helps but I used this program for a while (gfxCardStatus) https://gfx.io. [gfx.io.]
It's kinda handy for letting you know what gfx card is in use. You can also force either Discrete or Integrated.