linux

Last month, I built an all-AMD PC to try out Linux Gaming with Steam and Proton, and so I'd have a faster native Linux build machine for my various compilation tasks.

This month, Apple introduced the Mac Studio, and as a now full-time video producer, it was a no-brainer for me to upgrade from an M1 Mac mini.

My Mac Studio arrived Friday, and over the weekend, I spent some time benchmarking it against not only my M1 mini, but also my new AMD Ryzen 5 5600x PC build.

My Mac Studio's specs:

Last year, due to some extreme luck and help from a viewer, I picked up an AMD RX 6700 XT for MSRP (around $500).

My initial goal was to see if I could get the card working on a Raspberry Pi. Though my initial effort was fruitless, I've since hacked the driver to work through at least a few 'rings' of AMD's doorbell init process.

Update: I was able to get everything to work—but I couldn't get the RX 6700 XT's drivers installed in Ubuntu. There are probably a few reasons for that... but it definitely wasn't as straightforward as I had hoped. I'll post an update soon.

Last year, in my work towards bringing up a graphics card on the Raspberry Pi, I was fortunate enough to acquire an AMD Radeon RX 6700 XT at near-retail price (thanks to a viewer who assisted my luck!).

This year, as part of a slightly-zany video building a Raspberry Pi into a standard desktop PC, I was able to gather enough parts to make up a halfway-decent gaming/creative PC centered around the RX 6700 XT, and instead of putting it together myself, I thought I'd share in the potential disaster in a live stream—tune in at 10 a.m. US Central time on March 3 (or watch below):

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.

Video: This blog post is a companion piece to my video: Raspberry Pi does what Microsoft can't!

With a new Network Install feature, a Raspberry Pi can now set itself up—without any flash drive or other computer—directly over the Internet.

64-bits. More is always better, right?

Well, not exactly. And that's why it's taken years for Raspberry Pi OS to add an officially-supported 64-bit version, in addition to the 32-bit version they've had since the original Pi came out.

Since May 2020, there's been a beta 64-bit version of Pi OS, but it wasn't intended for beginners, and was never linked from the main downloads page.

You had to kinda be 'in the know' to get it. And the reason for that is it's actually branched directly off of Debian Linux and had a few growing pains. But almost all those problems have been ironed out now, and apparently it's time for the Raspberry Pi's 64-bit era.

For a recent project, I needed to add cellular connectivity to a Raspberry Pi (actually, an entire cluster... but that's a story for a future time!).

I figured I'd document the process in this blog post so people who follow in my footsteps don't need to spend quite as much time researching. This post is the culmination of 40+ hours of reading, testing, and head-scratching.

There doesn't seem to be any good central resource for "4G LTE and Linux" out there, just a thousand posts about the ABC's of getting an Internet connection working through a 4G modem—but with precious little explanation about why or how it works. (Or why someone should care about random terms like PPP, ECM, QMI, or MBIM, or why someone would choose qmi_wwan over cdc_ether, or ... I could go on).

Hopefully you can learn something from my notes. Or point out places where I'm glaringly wrong :)

As I start using Raspberry Pis for more and more network routing activities—especially as the Compute Module 4 routers based on Debian, OpenWRT, and VyOS have started appearing—I've been struggling with one particular problem: how can I set routing priorities for network interfaces?

Now, this is a bit of a loaded question. You could dive right into routing tables and start adding and deleting routes from the kernel. You could mess with subnets, modify firewalls, and futz with iptables.

But in my case, my need was simple: I wanted to test the speed of a specific interface, either from one computer to another, or over the Internet (e.g. via speedtest-cli).

The problem is, even if you try limiting an application to a specific IP address (each network interface has its own), the Linux kernel will choose whatever network route it deems the best.

Since the Raspberry Pi Compute Module 4 was introduced last year, I've been testing a variety of PCI Express NICs with it. One of the main types of NIC I'm interested in is cheap 2.5 Gigabit Ethernet adapters.

2.5 Gigabits is about the highest reasonable bandwidth you can get through the PCI Express Gen 2.0 x1 lane on the Raspberry Pi, and it's also a lot more accessible than 10 Gigabit networking, especially for home users who might already have Cat5e runs that they are loathe to swap out for Cat6 or better cabling.

In my testing, besides discovering that not all 10 Gbps SFP+ transceivers are created equal, I found out that when it comes to performance, the Linux driver you're using matters—a lot.

This is a simple guide, part of a series I'll call 'How-To Guide Without Ads'. In it, I'm going to document how I set up bcache on a Raspberry Pi, so I could use an SSD as a cache in front of a RAID array.

Getting bcache

bcache is sometimes used on Linux devices to allow a more efficient SSD cache to run in front of a single or multiple slower hard drives—typically in a storage array.

In my case, I have three SATA hard drives: /dev/sda, /dev/sdb, and /dev/sdc. And I have one NVMe SSD: /dev/nvme0n1.

I created a RAID5 array with mdadm for the three hard drives, and had the raid device /dev/md0.

I then installed bcache-tools:

$ sudo apt-get install bcache-tools

And used make-bcache to create the backing and cache devices: