I am having a fragment shader that locks the HW. No application can respond etc. In bootcamp everything works fine but when I have run the shader and reboots, the OSX will not start up ? I need to press the power button to get it to run again ?
Are you sure you didn’t just crash the GPU?
If you have another machine you can always try to ssh in and reboot it cleanly that way. I have had to do that a few times with my first ropey attempts at shaders!!