Have you tried in a full party raid? Which was my focal point, which I didn't specify, doh! Performance drops in raid from what I can tell. When I'm not in a raid, even on my dinky little 1060 I can do around 65~75 fps. But in raids, like VT hive queen for example, it goes down to like 25~35, making me a very sad panda. Something about being in a raid really chunks it out, but it seems to be ok on those weekly raids / msp. As to why, I have no clue. The optimization is all over the place.
But I am curious as to what numbers you got, it's interesting to see maths. I can get some numbers for ya after I get back tonight, I have a VT raid so I can get some hive queen numbers too.
And I don't wanna be a grandpa.. I'm old, but not that old.