Your 2011 iMac had a dedicated GPU (all old imacs had dedicated GPUs). The new 21.5 inch iMacs only have Intel integrated GPUs. So yeah, unfortunately while your new machine is in some ways far superior, it isn’t necessarily an all around upgrade. Your new machine has less graphics power for the game to work with, which is going to put a lot more strain on the CPU. In most cases this isn’t going to be a problem whatsoever and the CPU will handle things just fine, but for gaming, and especially for something like GW2, losing that dedicated GPU is going to have a negative impact on your experience.
Perhaps you earn your money with computer hardware and do know a lot more than me.
But I don’t think so. Clearly dedicated (vs integrated) GPU does not mean that per se it is better. From all that I can see those who analysed GPU performances found the “Intel Iris Pro Graphics 6200” superior to the older dedecated one in the iMac 2011.
The quality of the of the graphic – as long as the computer does not crash – on the new Mac ist good (better than on a window laptop with Gforce 860M).
I thought that GW2 does not use GPU intensively but requires a lot of CPU power. Clearely the new Mac is far superior in this regard and has lots more ram.
The Mac crashes with GW2 after a while even when graphically the situation seems not demanding. I therefore assume that the program has some issues with something other that GPU-power.
Yesterday I installed an new 21.5 inch iMac with retina display and in every (!) large event (Tequatel, Tarir, WVW zerks) I suffer crashes. Up to yestarday I used an 2011er iMac which was much more stabily running.
So, I also advocate for a better Mac-client performance.