Like a LOT of the questions on this forum, I've struggled with my choice of graphics card and researched endlessly to no avail.
So, I'm proposing a user led and at the moment quite subjective but informative test.
I've downloaded the Archicad training series volume one file which has a large building with plenty of triangles. You can google it and:
I'd love it if everyone who reads this and has the time to download this same file, show all layers in 3D and give it a spin, then post their results.