VideoMemorySizeMb I don't understand it?

[TheGamingGeneral]

I'm installing ENBoost with the S.T.E.P Guide and I don't understand what this formula means... "64-bit users with >= 8GB system RAM, set to formula: [Total Available Video Memory] - [170 (for win7) or 350 (for win8/10)]" for the line in my enblocal.ini. I have 16 GB of ram and 4 of VRAM and windows 8.1 64bit not sure what I should be putting... any help?

Edited June 17, 2015 by TheGamingGeneral

[TechAngel85]

https://wiki.step-project.com/Guide:ENBlocal_INI/Memory#VideoMemorySizeMb