The Raspberry Pi 4 Model B has launched. It's a pretty big upgrade from the Raspberry Pi 3, with the company claiming that the device can provide "desktop performance comparable to entry-level x86 PC systems."
OK... but how does it perform as a server? Individually, the answer is just about what you'd expect.
While the Pi 4B is an enormous all-around upgrade from the 3B+, it's still a Raspberry Pi at its heart. The former model's DDR2 RAM has been upgraded to DDR4, the new Cortex A72 CPU is anywhere from double to quadruple the speed of the older A53, and the gigabit Ethernet adapter isn't hamstrung by a USB 2.0 bus anymore, so it can actually push a gigabit worth of traffic. This is for a starting-at-$35, passively-cooled bittybox... but it's still very anemic compared to, for example, a humble i3-8100T.
But where you can't scale up, you can scale out—and that's precisely what www.raspberrypi.org has done. The launch site for the Raspberry Pi 4 Model B is mostly running on a cluster of 18 of the little devices themselves. Fourteen handle PHP code execution, two serve static files, and two run memcached. CloudFlare is still handling the brunt of the raw network traffic, though, and the database—by far the heaviest storage load on a WordPress site—isn't running on the little Pi cluster, either.
This is clearly a PR stunt writ large—no sensible sysadmin would want to have to maintain this thing as-is, and the most difficult bits still aren't running on Pi hardware at all. As Late Night Linux's Joe Ressington noted, the site appears to have been intermittently down on launch morning as well. Mythic Beasts blamed CDN host CloudFlare for the outage, but when I looked on CloudFlare's site, all of Ressington's area of the world (the UK) was reported fully operational. Regardless of hiccups, I strongly respect Mythic Beasts' hustle. Getting this thing working in the constraints the team had—deploying an 18-system cluster in a few hours on unfamiliar hardware, with a beta OS distribution, to handle the pressure of a massive hardware launch campaign—is a real achievement.
As for the Raspberry Pi 4 B itself—it's a compelling design. This is a Pi model that hangs with high-end single-board devices like the Odroid N2 while keeping the bottom-dollar price Pi enthusiasts are used to. If you're in the market for a single-board hobbyist device—and you can find one in stock this close to launch day—it looks like the Pi 4 B is the one to get.