Jeff Geerling
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Rejoice, leap seconds are dead!
There will never be a leap second again. At least not for UTC. At the CGPM , they decided the last leap second we'll ever see for UTC, or Coordinated Universal Time, happened back at the end of 2016 . Of course they made that decision while I was out on vacation, so I'm just getting this video up…
Noctua Fan Swap on a Calnex Rb/GPS Frequency Reference
Since this will be the only source of this process on the Internet 1 , I figured I'd document a quick fan swap I did on a piece of test/reference equipment I'm running in my Atomic Clock Tower . I took my Torx T10 screwdriver and popped off the top cover. The screws required some force to loosen…
Ubiquiti's $99 Vape Detector is actually pretty good
Since learning about the effects of high CO2 concentration on attention and cognitive performance—especially at levels much higher than 2000ppm—I've started monitoring CO2 and other air quality indicators in my house, at my studio, and even on the road. I have a few other air quality monitors I'll…
Upgrade your PHP installs immediately to protect against php2shell
This morning, two critical PHP Security Advisories were published: RCE via OOM corruption (9.2/10) RCE via stale global state (9.2/10) If you're running PHP for any service, you need to upgrade immediately to 8.2.35, 8.3.36, 8.4.27, or 8.5.12. And if you use Remi's repos on RedHat-derivative Linux…
Formlabs dropped the Raspberry Pi on the way to a $699 SLA printer
Formlabs sent me a Form Studio 1 resin 3D printer to test after years of back-and-forth about their Form 4 printer. Like the Form 4, it's an SLA (stereolithography) printer, but unlike the Form 4 (which starts at $2,600), it's affordable for a hobbyist. It's not cheap , coming in at $699 (or $749…
Radxa's Q8B has 2x the performance and expansion of the Pi 5
There was a time I'd look at a board like the Radxa Dragon Q8B (at left, above) and be like, "there's no way I'd spend $209 on an SBC with 8 gigs of RAM". But we're in 2026, and seeing the 8 gig Raspberry Pi 5 going for almost the same amount, I figured I'd give it a shot. On paper , the Q8B beats…
I'm starting HomelabFest (in St. Louis, Sep 2027)
I've been working on my homelab for years, and I enjoy sharing what I learn through this blog and my YouTube channel. Over the past few years, I realized the homelab community (which isn't really a defined thing—that's okay) hasn't had its own gathering, the way makers, software engineers, embedded…
Raspberry Pi locks down Pi 5 RAM upgrades in firmware
Raspberry Pi added a feature in their firmware that restricts users from swapping RAM chips , sometimes even RAM chips of the same capacity from other Raspberry Pi boards. Apparently there were people buying cheap 1 or 2 gig Pi 5s, soldering in some cheap and sometimes unreliable 8 gig RAM chips…
NTP, an atomic clock, and having a great time at the world's largest VCF
I'm back from VCF Midwest 21 , arguably the largest vintage computer festival on the planet. After being blown away last year, I decided to get a table of my own this year, to demonstrate NTP Time on a bunch of old Macs, representing every era up to the pinnacle of the PowerPC, an Xserve G5…
OpenNMC is an open replacement for expensive APC management cards
UPSes are typically the most boring part of your homelab, but they're important. One of their main jobs is to give servers time to shut down safely if the power goes out. Another job is to condition your power so your servers can run smoothly. To do both of those things well , you need a smart…
Rebuilding a 1995 GPS Time Server so I don't get Telstra'd
In June I purchased this TrueTime XL-AK time server , so I could learn more of the history of GPS-based time. I received it on June 22, and just 16 days later a similar GPS time server took down Australia's cell service for 12 hours ! I made a short video about it but put off digging into the…
Before NTP there were Time and Daytime
In building an NTP time demo on old Macs for VCF Midwest , I came across RFC 867 and RFC 868 , for the 'Daytime' and 'Time' Protocols, respectively. My first exposure to any form of network time was when I upgraded from a used PowerBook 180c to my first 'new' computer, a Power Mac G3, in 2000. With…
Building a mini Homelab that fits in my carry-on
I'm traveling to Chicago for VCF Midwest next month. I'll be demoing NTP time history on vintage Macs, with my own GPS-derived NTP service hosted on an Xserve G5, synced via NTP or a strange AppleTalk timing extension from the 1990s . So I built a little 'portable homelab' (pictured above) that…
Debugging Ubiquiti's 5G Backup on AT&T
For a mobile 'mini homelab' project I'm working on, I wanted to use 5G Internet as a primary 'on-to-go' connection, but still have the ability to plug in another Internet connection when I put the mobile rack I'm building in a fixed location. I'll have more on that project soon, but I figured this…
Getting the Steam Deck LCD working on a Raspberry Pi
The BOE TV070WXM-TV0 LCD used in the original Steam Deck can be had for around $30. It's a serviceable 7" touchscreen with 400 nits of brightness and a resolution of 1280x800 (for a sharp 216 ppi). The specs are a lot nicer than the Pi 7" Touch Display , which costs twice as much, with giant bezels…
Hands-on with Raspberry Pi's CM5 Programming Jig
In the before-times, when Raspberry Pi CM5s were (relatively) affordable, I built a number of Pi clusters ( example ), and one of the most annoying parts of the build was flashing Raspberry Pi OS to all the Pis. One, two, or even three Pis isn't a big deal, but once you hit 4+, the process of…
I'm excited for Intel after testing the XPS 13
Shortly after Apple launched the budget MacBook Neo , Dell announced their response, a new low-end XPS 13 . Matching the Neo's current pricing, it starts at $699, or $599 with an educational discount. That discount is currently set to expire on November 2, and with the current component pricing…
Proxmox officially supports Arm, with some caveats
Proxmox today announced their Proxmox Virtual Environment is now available for 64-bit ARM . I tested it on my Ampere Altra Dev Platform —the same machine on which I've booted Windows on Arm the first time, messed with multiple GPUs, and most recently tested Houdini's native arm64 support . Install…
Getting 25 Gbps Thunderbolt Ethernet on my Mac Studio
I've been using the built-in 10 Gigabit Ethernet on my Mac Studio for a few years. It works fine: I can edit 4K video straight off my NAS over the network, and run backups at around 1 GB/sec. But... I want more . I upgraded my rack and my NAS to 25 GbE a couple years ago, and wanted to upgrade my…
Adding a backup Internet WAN on my OPNsense Router
AKA "Spectrum has gone down two weeks in a row and I'm sick of it". I've been borrowing a portable 5G gateway from my Dad for a few weeks, for testing... and two weeks in a row, I've used it as a backup Internet option, since my Spectrum Business cable Internet has gone down. And yes, I'd get AT&T…
In the directory since 14 Oct 2026 · last checked 9 Nov 2026 · RSS