Going up the GPU hierarchy resulting in lower frame rates (?)

[Pipe & Slippers]

Playing Path of Exile on Steam - the only game I play and that’s very intermittently
I‘m on a bit more than a HD monitor, playing windowed, so slightly less than 1920 x 1200

In February I upgraded from a 1060 6Gb to a 1070. I noticed that the frame rate seemed to drop from a pretty steady 60 occasionally 45, to mid 40’s and only ocassionaly getting up to a steady 60. Didn’t bother me too much since for me it was still pretty playable
I’ve just upgraded again to a 1080ti (in the now seemingly laughable hope of playing on my 4k screen!) and spent 30 mins gaming and the frame counter (I assume this is the steam one) seems to be more in the 30’s and 40’s. At one point it was stuck in the mid 20’s for what seemed like ages but was probably tens of seconds

Am I just noticing the extremes or is steam playing up, or does anyone have any insights?
I’m wondering if my system is unbalanced in some way, or maybe my brain is unbalanced…perhaps I should have stuck with the 1060

 

[Pipe & Slippers]

Cheers folks. Will do as you suggested when I get the opportunity

 

[Pipe & Slippers]

Rather shamefully, uninstalling and reinstalling the drivers sorted the issue
18 years on the forum and I didn’t think to do that myself <<cringe>>

BTW despite it being in a itx case, the gpu temps were v modest and no cause for concern and cpu load hovered around 50%, so all good

Thanks for your advice!