I've tried several thing to resolve this issue:
1. Stopped all sleep functions in Yosemite (and disabled AppNap)
2. Stopped Yosemite from slowing down SSD to conserve energy
3. Disabled all graphics optimations
4. Installed VMTools
5. added mks.gl.use32core = "TRUE" to .vmx file
Nothing works!
I was hoping that someone had ideas to fix this problem or could open up a support issue to confirm the problem on Mac OX Yosemite.