Can we update the guide per this: https://connect.microsoft.com/VisualStudio/feedback/details/1263324/gpu-memory-allocation-limit-on-directx9-windows-8
Boris (the ENBSeries guy) has mentioned in a few places now that people running Windows 8 and above (including Windows 10) will not be able to use the same strategy that Phase 3 uses to calculate the value for VideoMemorySizeMb. Instead, the STEP folks have started recommending using the DX9 version of http://enbdev.com/download_vramsizetest.htm to figure out the true value. It caps out at 4064 MB no matter how much VRAM and System RAM you have.