With Apple making external GPUs (eGPUs) a reality in macOS 10.13, I've decided to wait as long as I need to until Apple releases a computer with Thunderbolt 4, specifically on a MacBook Pro. (32 GB DDR4L RAM might come as well by then.) If you look at my short post history, you might doubt me because at first I thought I was going to buy a Razer Blade Pro after Apple's dismal showing of rMBPs (imo) and then just today I said I was going to wait for the Mac Pro. In my mind native support for external GPUs on macOS was an absolute pipe dream. But then I ran across the external GPU Development Kit, and I'm absolutely locked into Apple for my next computer because of this. Currently, the Alpine Ridge TB3 controller has 40Gb/s throughput per port, and while there is enough bandwidth to run a GPU decently, think about the compute-heavy/high-end GPUs like the GTX 1080 or any workstation GPU – they will certainly run into the TB3 bottleneck. (I haven't done enough in-depth research to know how much a GPU's performance will be affected.) Since bandwidth has doubled with every iteration of TB, it's sensible to think TB4 will have 80Gb/s throughput per port. With that, I'll finally be able to run a gaming or workstation-class GPU from a laptop and have the setup of my dreams - portability when I need it; and graphics, compute power, a docking station, and charging when I need it at home, all through one cable. If you've been waiting for external GPUs, or something like this, wait for TB4 because high-end GPUs might still be significantly bottlenecked - I remember reading a long while ago that TB2 could run a GTX750 at only 85% of max performance. I'm willing to wait up to 3 years from date of posting. Perhaps it might come out earlier, who knows. Thoughts? Comments? Estimations on % of GPU performance lost due to TB3/hypothetical TB4 bandwidth constraints?