I am using 2 WX 7100 graphics card and S400 synchronization module, and connect 8 monitors.
And the driver version is 18.Q3. and the OS is windows 10.
Amd said that with 18.Q3 we can configure multi gpu eyefinity.
We successfully 7680*2160 (Full HD 4 by 2) single large desktop with this driver,
but in this configuration. Synchronization menu in the Radeon Pro Settins is gone.