my template for the GPU cores has always been, diff of less than 5o on all of them, perfect. diff of less than 10o, you're ok. diff of >10o, crappy thermal paste job. diff of >15o, mad caking and flaking going on, diff of >20o, jesus, open that shit and fix it.
usually the case on those is that someone has applied too much thermal paste. like there'll be flakes and big chunks of that crap everywhere
I thought the exact same thing, or someone forgot to put some thermal tape on! but I have looked high and low and could not find a single person who has the same temp difference as I do, also I worry about these temps, being in a 20c ambient temp room with the window open, in the winter which results in these temps leaves me to believe I'm gonna have a hell of a time with temps in +30c to +40c come summer time