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 .
Visit jeffgeerling.com → RSS feedOn Hacker News Mar 2016 – Jul 2026
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The QuadRF (pictured above) a phased-array radio built around a Raspberry Pi 5 and an FPGA board with picosecond-level timing. It does advanced signal processing and beamforming. It can see WiFi through walls and track drones in flight. If the open source community can come up with something like this, just imagine…
Today Raspberry Pi announced more price increases for all Pis with LPDDR4 RAM, alongside a 'right-sized' 3GB RAM Pi 4 for $83.75. The price increases bring the 16GB Pi 5 up to $299.99. Despite today's date, this is not a joke. I published a video going over the state of the hobbyist 'high end SBC' market (4/8/16 GB…
For years, the best way to get 10 gigabit networking on laptops was to buy an expensive, large, and hot 10 GbE Thunderbolt adapter. With new RTL8159-based 10G USB 3.2 adapters coming onto the market, the bulky adapters might be a thing of the past. Just look at the size of the thing in comparison to my Thunderbolt…
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…
I had to pause some of my work getting a current-gen AMD graphics card running on the Pi 5 and testing a 192-core AmpereOne server to quickly post on the M4's efficiency. I expected M4 to be better than M1/M2 (I haven't personally tested M3), and I hoped it would at least match the previous total-system-power…
December 2020 Update: Lo and behold, the Pi Foundation tacitly acknowledges the Pi needs a fan in the official case, because now they sell the Case Fan! The Raspberry Pi Foundation's Pi 4 announcement blog post touted the Pi 4 as providing "PC-like level of performance for most users". The Foundation even offers a…
tl;dr: After two weeks of use, I returned my 2016 13" MacBook Pro with Touch Bar and bought one with Function Keys instead. Read on for detailed Battery stress tests, performance tests, and an exploration of how Apple's botched this year's Pro lineup. I've owned almost every generation of Mac desktop and laptop…
A few months ago, I found this Hacker News post about the AirGradient DIY Air Quality Monitor. I had already been considering buying an AirThings Wave Plus sensor to monitor my home's CO2 levels, but the high price and limited 'ownership' of the data coming from it turned me off. So I built two AirGradient DIY air…
SpaceX's Starlink internet service uses satellites in low-earth orbit to provide high-speed Internet to underserved parts of the world, especially places without easy access to cable or fiber. SpaceX's Starlink beta opened up in my area, so I installed Dishy—that's the nickname for the large white satellite dish…
You can view a video related to this blog post here: Does UASP make the Raspberry Pi faster?. A couple weeks ago, I did some testing with my Raspberry Pi 4 and external USB SSD drives. I found a USB 3.0 SSD was ten times faster than the fastest microSD card I tested. In the comments on the video associated with that…
I ordered a set of 10 Compute Blades in April 2023 (two years ago), and they just arrived a few weeks ago. In that time Raspberry Pi upgraded the CM4 to a CM5, so I ordered a set of 10 16GB CM5 Lite modules for my blade cluster. That should give me 160 GB of total RAM to play with. This was the biggest Pi cluster I've…
I'm in the process of rebuilding my homelab from the ground up, moving from a 24U full-size 4-post rack to a mini rack. One of the most difficult devices to downsize (especially economically) is a NAS. But as my needs have changed, I'm bucking the trend of all datahoarders and I need less storage than the 120 TB (80…
I've had a long history playing around with Raspberry Pis and other Single Board Computers (SBCs); from building a cluster of Raspberry Pis to run Drupal, to building a distributed home temperature monitoring system with Raspberry Pis, I've spent a good deal of time testing the limits of an SBC, and also finding ways…
A few months ago, I upgraded my M4 Mac mini from 1 to 2 TB of internal storage, using a then-$269 DIY upgrade kit from ExpandMacMini. At the time, there was no option for upgrading the M4 Pro Mac mini, despite it also using a user-replaceable, socketed storage drive. But the folks at M4-SSD reached out and asked if…
In March, I got an email from SpaceX saying Starlink was available at my address, and I could pre-order. I paid $500 for the equipment, plus $25 for a Volcano Roof Mount, and $99 for the first month of service, and a few weeks later, I got the kit you see in the image above. I was a little too excited about getting…
My nephew just graduated high school, and wants a laptop. When he decides what computer to buy, price (or more precisely, value) is the most important attribute. Apple's MacBook Neo upended the 'value laptop' equation—Apple's not supposed to be both the cheapest option and the best value... but it seems like that's…
A few months ago someone told me about a new Raspberry Pi Compute Module 4 cluster board, the DeskPi Super6c. You may have heard of another Pi CM4 cluster board, the Turing Pi 2, but that board is not yet shipping. It had a very successful Kickstarter campaign, but production has been delayed due to parts shortages…
A few months ago, our AM radio hot dog experiment went mildly viral. That was a result of me asking my Dad 'what would happen if you ground a hot dog to one of your AM radio towers?' He didn't know, so one night on the way to my son's volleyball practice, we tested it. And it was awesome. There's a video and some…
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…
When the Compute Module 4 was released (see my CM4 review here), I asked the Pi Foundation engineers when we might be able to boot off NVMe storage, since it was trivially easy to use with the exposed PCIe x1 lane on the CM4 IO Board. The initial response in October 2020 was "we'll see". Luckily, after more people…
This is the Compute Blade, and I'm test driving it in a four-node cluster: I'm testing the Dev version, and @Merocle from Uptime Lab sent four Blades, a 3D-printed 4-bay case (a metal 1U rackmount enclosure is in the works), and two fan modules. He's been testing 40 of these in a rack at Jetbrains for months, and…
I've been following WisdPi's development of various 5 Gbps and 10 Gbps Ethernet adapters for the past couple years. They use newer Realtek Ethernet chips, which sometimes have performance quirks—most frequently encountered under Linux. In today's video, I tested the new WisdPi 10G Ethernet Expansion Card for Framework…
(With a caveat: I'm compiling the ARMv8 64-bit Pi OS kernel.) It seems every week or so on Hacker News, a story hits the front page showing some new benchmark and how one of the new M1-based Macs matches or beats the higher-priced competition in some specific benchmark—be it GeekBench, X86-specific code, or building…
January 1, 2021 Update: My 1.34 Gbps benchmark was flawed. See this GitHub issue and this updated blog post to learn more: WiFi 6 is not faster than Ethernet on the Raspberry Pi. After buying three wireless cards, a new WiFi router, optimizing my process for cross-compiling the Linux kernel for the Raspberry Pi…
tl;dr: it depends. About one year ago, I bought an Intel N100 mini PC (specifically the GMKtec N100 NucBox G3) and compared it to the Raspberry Pi 5 8GB. A year later, and we have a newer $159 16GB version of that mini PC with a slightly-faster Intel N150, and a new 16GB Raspberry Pi 5. I re-ran all my benchmarks, and…
Ever since the Pi 2 model B went to a 4-core processor, disk IO has often been the primary bottleneck for my Pi projects. You can use microSD cards, which aren't horrible, but... well, nevermind, they're pretty bad as a primary disk. Or you can plug in a USB 3.0 SSD and get decent speed, but you end up with a cabling…
...or at least, not without a lot of patience or a fat wallet. But why? And are there any signs Raspberry Pis will become available to the general public again soon? To be clear, I'm speaking of the mainstream SBC Raspberry Pis, like the Pi 4 model B, the Compute Module 4, the Pi Zero 2 W, and even in many cases the…
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…
Back in 2015, I wrote a popular post comparing the performance of a number of microSD cards when used with the Raspberry Pi. In the intervening three years, the marketplace hasn't changed a ton, but there have been two new revisions to the Raspberry Pi (the model 3 B and just-released model 3 B+). In that article, I…
I've used Macs as my primary computing devices my entire life. And though I continue to use a Mac for my primary workstation for both work and personal projects, my use of computers has evolved in the past few years quite a bit. With more of my stuff moving into the cloud and fewer software applications being…