OK so got it going perfectly now.
The drivers on the NVidia website are 353.30 - do not install.
Instead - install drivers 353.62 - either by downloading from guru3d or by installing old drivers(347.52 work) and then allowing GeForce to upgrade you to 353.62 and do a fresh install.
SLI is now enabled - good to go
The drivers on the NVidia website are 353.30 - do not install.
Instead - install drivers 353.62 - either by downloading from guru3d or by installing old drivers(347.52 work) and then allowing GeForce to upgrade you to 353.62 and do a fresh install.
SLI is now enabled - good to go