How to turn on or off for "CUDA 8 UNIFIED MEMORY"

Super long time, I was waiting for “CUDA 8 Toolkit GA”.
As you know, “CUDA 8 UNIFIED MEMORY” is very simple for a newcomer.
Unfortunately I only have 2 set of “GeForce GTX 960”.

CUDA Capability Major/Minor version number: 5.2

Q1: How and when could we turn on or off for “CUDA 8 UNIFIED MEMORY”?

Q2: Should I buy a new GeForce GTX 10xx/Pascal for trying the feature?

Q3: Should I NOT install CUDA 8 until GTX 10xx/Pascal is installed?