HBM should be good, if spec sheets are accurate,
4GB of VRAM, but only taking the spots on the PCB of maybe 4 chips instead of 16.

Makes room to allow one big GPU chip, with a AiO Water cooler slapped on it out of the box.

Thats likely not even the top end GPU either. (Rx-390).

However, the power draw of 2 lightnings is ~500watts, takes up 4 total slots, and Xfire isnt garaunteed performance.

So I can drop ~200w Any Xfire incompatibilities, get faster memory, VSR and all the latest driver things that arent working for 7000 series etc, free up 2 slots, abd save on heat etc as it will.be water cooled out of the box.

Keep a 7970 lightning as a backup, and give the other one to my brother.

My issue is whether or not it will suffer on PCIe 2.0