Aye, Abwx is on the money 'ere. The "CPU Framerate" was stated to be a guesstimate if the CPU had some not-bottlenecked-anywhere graphics card tied tae it. 'Tis not even a synthetic benchmark, so it's just stupid and/or dishonest ta portray it as some sort of decent indicator.
'Tis the other framerate scores that matter, and aye. GPUs aren't created equal when handling draw calls. For example, we ken that NVidia has a software scheduler for Maxwell 'n' Pascal (defo' fer Maxie, not too sure about Pascie, actually), and that AMD's GCN graphics cards have hardware schedulers. And it's not as if it's the same damn one; architecture changes 'n' all that.
And that ain't even taking into driver differences between brands, architectures and individual cards.
Get the CPUs, disable turbo 'n' set them all tae the slowest chip's clocks, slap three 980 ti's on each of 'em and send off the results. If we ain't got that, the comparisons are 'tarded at best.