The important part is here: "64 bit format. This has good precision, and also leaves us with another channel were we can store an extra attribute" In other words, it can draw paralax textures (google it, if you don't know, what that means) "32-bit wide RenderTargets. In order to use this, you only store the depth of the pixel, instead of the whole position." It is the good old regular rendering option. Consumes less memory, but doesn't look as good with deferred lightning, and can't use paralax. I'm pretty sure, that the base game textures don't contain paralax information, but if you have textures packs like Vivid Textures installed, it makes sense to enable 64 bit rendering.