Just showing how my hardware plays WoW. I use default settings.

Also, I didn't know the fight 100% (hardly play WoW these days)

As you can see, during the fight, frames don't drop below 40. Outside of cities and raid encounters, I was averagine 90+ frames

Full Specs are

AMD Ryzen 1700 Stock Clock
AMD RX580 8gb Gddr5
8GB (x1) 2400 DDR4 RAM
250 GB Samsung 850 SSD