Hey everyone! I work at a production house that is looking into getting an iMac for video production. We usually use 4-6 cameras per shoot, and have multiple AE text templates that we dynamic link into the premiere timeline. I've narrowed down our options to two iMacs. It looks like our tradeoff is an objectively faster GPU (AMD) with 2gb of video memory and a quad core i5 which can't hyper thread, OR a slower GPU (intel iris) and an i7 which is capable of hyper threading. All other things being equal, and screen size ignored, which is the better option for us? We are also going to get an external SSD for scratch connected via FireWire.
the 27" r9 m390 and m395 models will let you select the i7, after that its deciding how much gpu power you need. the more gpu accelerated fx or plugins a project/timeline has, the more important a faster gpu will be. 32gb of memory and the 4gb m395x would be good for editing premiere pro 4k timelines. i would also recommend choosing a flash drive vs fusion. external usb or thunderbolt ssd would also be much faster than firewire.