I wanted to have the most accurate timepiece possible mounted in my mini rack. Therefore I built this:

This is a GPS-based clock running on a Raspberry Pi Pico in a custom 1U 10" rack faceplate. The clock displays time based on a GPS input, and will not display time until a GPS timing lock has been acquired.

• When you turn on the Pico, the display reads ----
• Upon 3D fix, you get a time on the clock, and the colon starts blinking
• If the 3D fix is lost, the colon goes solid
• When the 3D fix is regained, the colon starts blinking again

For full details on designing and building this clock, see:

For the past decade, I've used Mailhog for local email debugging. Besides working on web applications that deal with email, I've long used email as the primary notification system for comments on the blog.

I built an Ansible role for Mailhog, and it was one of the main features of Drupal VM, a popular local development environment for Drupal I sunset 3 years ago.

Unfortunately, barring any future updates from the maintainers, it seems like Mailhog has not been maintained for four years now. It still works, but something as complex as an email debugging environment needs ongoing maintenance to stay relevant.

Almost a year ago, I found that N100 Mini PCs were cheaper than a decked-out Raspberry Pi 5. So comparing systems with:

• 16GB of RAM
• 512GB NVMe SSD
• Including case, cooler, and power adapter

Back in March last year, a GMKtec Mini PC was $159, and a similar-spec Pi 5 was $208.

Today? The same GMKtec Mini PC is $246.99, and the same Pi 5 is $246.95:

Today, because of the wonderful RAM shortages¹, the Mini PC is the same price as a fully kitted-out Raspberry Pi 5.

Last month, the stars aligned for me to bring the Mono Gateway (a 10 Gbps router that YouTuber Tomaž Zaman and his team at Mono built from scratch) on a trip to Phoenix, and test it with one of the most OP network test boxes I've ever seen, at the ServeTheHome HQ.

In this video, Patrick (from STH) and I put Gateway through a real-world torture test using CyPerf:

Mono Gateway

The Gateway is a small (1U/desktop) router with features like a 4-core Arm CPU, 8GB of ECC LPDDR RAM, and decent expansion options for a compact router.

Since 2009, this website has run on Drupal. Starting with Drupal 6, and progressing through major site upgrades and migrations to 7, 8, 9, and 10, I used the site as a way to dogfood the same CMS (Content Management System) I used in my day job for over a decade.

But as time progressed—especially after completing a grueling upgrade from Drupal 7 to 8—my enthusiasm for maintaining what's now a more enterprise-focused Digital Experience Platform or 'DXP' for a personal blog has waned.

Testing the Mono Gateway, a custom-built 10 Gbps Router Jeff Geerling January 2, 2026

Dell's version of the DGX Spark fixes pain points Jeff Geerling December 26, 2025

Dell sent me two of their GB10 mini workstations to test:

In this blog post, I'll cover the base system, just one of the two nodes. Cluster testing is ongoing, and I'll cover things like AI model training and networking more in depth next year, likely with comparisons to the Framework Desktop cluster and Mac Studio cluster I've also been testing.

But many of the same caveats of the DGX Spark (namely, price to performance is not great if you just want to run LLMs on a small desktop) apply to Dell's GB10 box as well.

NIST was 5 μs off UTC after last week's power cut Jeff Geerling December 22, 2025

If you were 5 microseconds late today, blame it on NIST.

Their facility in Boulder Colorado just had its power cut for multiple days. After a backup generator failed, their main ensemble clock lost track of UTC, or Universal Time Coordinated.

But even if you used the NTP timing servers they run, they were never off by more than 5 microseconds.

5 μs might seem insignificant. But it is significant for scientists and universities who rely on NIST's more specialized timing signals.

Big GPUs don't need big PCs Jeff Geerling December 20, 2025

Ever since I got AMD, Intel, and Nvidia graphics cards to run on a Raspberry Pi, I had a nagging question:

What's the point?

The Raspberry Pi only has 1 lane of PCIe Gen 3 bandwidth available for a connection to an eGPU. That's not much. Especially considering a modern desktop has at least one slot with 16 lanes of PCIe Gen 5 bandwidth. That's 8 GT/s versus 512 GT/s. Not a fair fight.

1.5 TB of VRAM on Mac Studio - RDMA over Thunderbolt 5 Jeff Geerling December 18, 2025

Apple gave me access to this Mac Studio cluster to test RDMA over Thunderbolt, a new feature in macOS 26.2. The easiest way to test it is with Exo 1.0, an open source private AI clustering tool. RDMA lets the Macs all act like they have one giant pool of RAM, which speeds up things like massive AI models.

The stack of Macs I tested, with 1.5 TB of unified memory, costs just shy of $40,000, and if you're wondering, no I cannot justify spending that much money for this. Apple loaned the Mac Studios for testing. I also have to thank DeskPi for sending over the 4-post mini rack containing the cluster.

CM0 - a new Raspberry Pi you can't buy Jeff Geerling December 12, 2025

This little postage stamp is actually a full Raspberry Pi Zero 2, complete with eMMC storage and WiFi.

But you can't get one. Well, not unless you buy the CM0NANO development board from EDAtec, or you live in China.

This little guy doesn't have an HDMI port, Ethernet, or even USB. It's a special version of the 'Compute Module' line of boards. Little Raspberry Pi 'System on Modules' (SoMs), they're called.

Benchmarking NVENC video transcoding on the Pi Jeff Geerling December 11, 2025

Now that Nvidia GPUs run on the Raspberry Pi, I've been putting all the ones I own through their paces.

Many people have an older Nvidia card (like a 3060) laying around from an upgrade. So could a Pi be suitable for GPU-accelerated video transcoding, either standalone for conversion, or running something like Jellyfin for video library management and streaming?

That's what I set out to do, and the first step, besides getting the drivers and CUDA going (see blog post linked above), was to find a way to get a repeatable benchmark going.

The DC-ROMA II is the fastest RISC-V laptop and is odd Jeff Geerling December 8, 2025

Inside this Framework 13 laptop is a special mainboard developed by DeepComputing in collaboration with Framework. It has an 8-core RISC-V processor, the ESWIN 7702X—not your typical AMD, Intel, or even Arm SoC. The full laptop version I tested costs $1119 and gets you about the performance of a Raspberry Pi.

A Pi 4—the one that came out in 2019.

But unlike the Pi 4, this eats up 25 watts of power at idle, meaning the poor battery only lasts 2-3 hours.

The RAM Shortage Comes for Us All Jeff Geerling December 4, 2025

Memory price inflation comes for us all, and if you're not affected yet, just wait.

I was building a new PC last month using some parts I had bought earlier this year. The 64 Gigabyte T-Create DDR5 memory kit I used cost $209 then. Today? The same kit costs $650!

Just in the past week, we found out Raspberry Pi's increasing their single board computer prices. Micron's killing the Crucial brand of RAM and storage devices completely, meaning there's gonna be one fewer consumer memory manufacturer. Samsung can't even buy RAM from themselves to build their own Smartphones, and small vendors like Libre Computer and Mono are seeing RAM prices double, triple, or even worse, and they're not even buying the latest RAM tech!

Why doesn't Apple make a standalone Touch ID? Jeff Geerling December 3, 2025

I finally upgraded to a mechanical keyboard. But because Apple's so protective of their Touch ID hardware, there aren't any mechanical keyboards with that feature built in.

But there is a way to hack it. It's incredibly wasteful, and takes a bit more patience than I think most people have, but you basically take an Apple Magic Keyboard with Touch ID, rip out the Touch ID, and install it in a 3D printed box, along with the keyboard's logic board.

Nvidia Graphics Cards work on Pi 5 and Rockchip Jeff Geerling November 26, 2025

A few months ago, GitHub user @yanghaku dropped a 15 line patch to fix GPU support for practically all AMD GPUs on the Raspberry Pi (and demoed a 3080 running on the Pi with a separate, unreleased patch). This week, GitHub user @mariobalanica dropped this (larger) patch which does the same for Nvidia GPUs!

I have a Raspberry Pi and an Nvidia graphics card—and I'm easily distracted. So I put down my testing of a GB10 system for a bit, and compiled mariobalanica's branch.

Air Lab is the Flipper Zero of air quality monitors Jeff Geerling November 21, 2025

This air quality monitor costs $250. It's called the Air Lab, and I've been using it to measure the air in my car, home, studio, and a few events over the past few months. And in using it over the course of a road trip I learned to not run recirculate in my car quite as often—more on that later.

Networked Artifacts built in some personality:

How to silence the fan on a CM5 after shutdown Jeff Geerling November 20, 2025

Out of the box, if you buy a Raspberry Pi Compute Module 5, install it on the official CM5 IO Board, and install a fan on it (e.g. my current favorite, the EDAtec CM5 Active Cooler), you'll notice the fan ramps up to 100% speed after you shut down the Pi.

That's not fun, since at least for a couple of my CM5s, they are more often powered down than running, creating a slight cacophany!