I am thinking update my gtx 775m 27” iMac to a 2017 base model 27” 5k iMac. My worry is if the gpu can handle the screen now? In the past I have noticed a lot of people complaining about the performance of retina Macs( Regina MacBook Pro and 4K or 5k iMacs). They are lag and slow especially in Ui animation even just in light daily use because the gpu are not good enough to handle the high resolution screens which is so disappointing since it’s an expensive machine. As the gpu got a big update in 2017. I assume it will works fine now? So anyone has the base model of 2017 27” iMac can tell me if it works well without any lag or something like that? Thanks!