Hi Mike,

> I also see four cores working, but that's because 2 cores are hyper-threaded to four.

Hmm but when you set the limit in MoI to 2 that should mean only 2 threads (so 2 entries in the task manager) are crunching away with possibly some amount on a third thread where it is talking to the driver on the main thread.

If you still see 4 cores going, that sounds like the driver is still using multiple threads itself despite that particular "Threaded optimization" setting being turned off. I was going to say try the global setting instead of the per-app one but I just saw that you tried that already.

Is it possible that there is a separate Direct3D and OpenGL sections for driver settings? You would want to be in the Direct3D one if so.

Otherwise, some generic advice might be to upgrade to the latest video driver if you are on an older version, maybe there was a problem at some point with it not paying attention to the threaded optimization setting...

- Michael