Following some advice I saw in other threads about DX11, I underclocked my GPU by 100MHz for the core and the memory by 500MHz. I also lowered the power draw to 90%. My GPU was never overclocked in the first place as an fyi. I was playing fine today for about 4 hours without the black screen. Its still too early to tell as I've seen it appear very shortly after logging on or after many hours of gameplay in one day.
If after a few days it stays stable, I would still like to point to FF14 as other games running at stock speed did not have this issue. But again, too early to tell.
