I often like exploring what's possible on a Raspberry Pi (or other low-end hardware). One area I haven't explored much is GPU performance. I typically run my Pi's headless, and have only dabbled in embedded machine vision with Pi cameras, so most of my experience is on the programming / software side.
But seeing Apple's 120 Hz 'ProMotion', and ever-higher refresh rates in the enthusiast gaming realm (we may hit 480 Hz soon!), I wanted to see how a tiny Raspberry Pi could perform in this realm.
The Pi's VideoCore GPU can output 1080p at refresh rates up to 120 Hz—at least there's a setting for it. But I'd never tried it. The hardest I pushed a Pi was 4K at 60 Hz for my Pi 4 a Day challenge, and that didn't go as well as I'd hoped.
From home temperature monitoring to a Kubernetes cluster hosting a live Drupal website, I have a lot of experience running Raspberry Pis. I've used every model through the years, and am currently using a mix of A+, 2 model B, and 4 model B Pis.
The 3 model B+ was the first generation that had me concerned more about cooling (the CPU gets hot!), and the Pi 4's slightly increased performance made that problem even more apparent, as most of my heavier projects resulted in CPU throttling. I've written about how the Raspberry Pi 4 needs a fan, and more recently how it might not.
August 2017 update: I just noticed the tech specs on the Arc Hub product page have changed to read: "Arc Hub comes with 1 x Mini Display Port 1.2. Capable resolutions are all HiDPI resolutions, 1080p@60hz, 2560 x 1440 @ 60hz, 3840×2160@30hz." The tech specs used to mention 4K at 60Hz ?.
I've since switched to a CalDigit TS3 Plus and couldn't be happier!
original tl;dr: A capable hub, with some slight design flaws. However, not yet recommended if you want to use it with a 4K monitor, due to compatibility issues with higher refresh rates.