I think a larger memory controller and higher amounts of ram would also be important.
I wonder how high a chip can clock on 12nm or heck even 16nm .. gotta be cheap to use that process now
Lets see... VSA-100 2.0. ... 14nm GF lines ought to be available, or Samsungs. You'd probably be able to clock them quite a bit. Slap in some DDR4 (could possibly be overkill, anything is better than the SDRAM that was in it to begin with) or even HBM for packaging reasons. PCIe, obviously.
With how much smaller the components would be you could even shrink the design and make a "mini" Voodoo 5 6000.