Vjeran Pavic writing for The Verge:
"Apple just wrapped up one of the most hardware-focused software conferences ever. Aside from updating existing products like the MacBook with new Kaby Lake processors, and announcing the new Siri-enabled HomePod speaker, Apple decided to use WWDC to please its pro users with new iMac and iMac Pro desktop computers.
The new iMac Pro won’t ship until December, but the speed-bumped iMacs are something pro users can buy today. It's been a while since we've upgraded the iMacs in our offices, and we're currently in the midst of a switch over to 4K video editing. Combine those two factors and you can guess that we spend a lot of time staring at progress bars.
So in the short time we had, we wanted to focus on the performance of one of the updated iMacs and see how it handles 4K video editing. I set one up at my normal workstation at The Verge just a couple days ago, and have been editing 4K video (and large photo files) since then. And the difference in performance has been instantly evident."