I tested System76 Thelio Mira: the custom Linux desktop of my dreams

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Sure, you can build a more powerful Linux workstation, but even then, you’d be hard-pressed to make a better machine than System76’s new 2026. Thelio Mira Custom desktop PC. That is because the computer is very powerful and whisper quiet.

The 2026 Mira update is built around AMD’s Ryzen 9000 “Granite Ridge” platform on the X870 motherboard. This setup gives you PCIe 5.0 for GPUs and SSDs, providing up to 32 gigatransfers per second (GT/s) per lane, which adds up to 64 gigabytes per second (GB/s) and 128 GB/s for double throughput. Combine that power with Gen5 Non-Volatile Memory Express (NVMe) sequential throughput of up to 15 GB/s, and we’re talking very fast I/O.

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That’s a good thing, because Mira Custom CPU options range from a 6-core Ryzen 5 9600X at the low end all the way up to a 16-core Ryzen 9 9950X or 9950X3D, with advertised boost clocks of up to 5.7 GHz on the top SKUs. In my case, I have a 16-core Ryzen 9 9950X clocked at 4.3 GHz. When I put the pedal to the metal, it was emitting at 5.7 GHz.

For graphics, I could have used integrated Ryzen graphics, but my PC came with an Nvidia GeForce RTX 5070 with 12 GB of VRAM. That capability is fine for today’s 1080p/1440p games, but not enough VRAM for high-end competitive 4K gaming.

You can also connect displays to both graphics outputs and run System76’s default Linux operating system, Pop!_OS, which provides on-the-fly GPU switching via a graphical interface. In addition, you can assign certain applications to run on the specific GPU. So, for example, you can use Ryzen to run graphics while handing over GeForce to AI workloads.

AI beauty

Speaking of AI, the Nvidia card is a solid mid-range entry-level engine. The card is great for 7-8B models like the Llama 3.x/3.1 8B, Qwen2.5-7B/8B, or Mistral Small 3 7B. I would call it “okay but strong” for 12-16B LLMs like Qwen3/Qwen2.5 14B, Llama 3.x/3.1 15B, or Gemma 3 around 12-14B. That said, the Ryzen 9 9950X is an excellent CPU-side workhorse for AI tools, fine-tuning, and mixed creative workloads.

Another AI plus is its fluid-cooled design and improved power delivery. This PC is clearly designed to support high clocks under long-term workloads, which is exactly what you want for hours of fine-tuning or batch AI generation. System76 claims a performance increase of up to 19% and a 13-degree temperature drop compared to the previous air-cooled design.

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Liquid cooling also makes the PC whisper quiet. I honestly couldn’t tell if the machine was working at times, even when going through big jobs.

Helping with all this functionality, Pop!_OS Linux comes with first-class Nvidia CUDA drivers in the box. You can install the Nvidia CUDA Toolkit via Pop!_Shop or with a single command without worrying about dependency conflicts:

$ sudo should install system76-cuda-latest

In short, Thelio Mira is a “ready-to-work” AI workstation.

Memory, storage, and expansion

System76 supports up to 192 GB of dual-channel DDR5 with four DIMM slots, with a 4 × 48 GB configuration running at 3,600 MHz and low-power modules up to 5,600 MHz. My test system came with 64 GB of RAM.

The X870 motherboard technically supports clocks up to 256 GB and higher memory with overclocking. However, the certified configuration of System76 stands at 192 GB, which is more than enough for most workstation tasks.

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Storage is where the Mira Custom really shines for power users: you get three M.2 NVMe slots (PCIe Gen5, Gen4, and Gen3) and at least two 2.5-inch SATA ports, allowing you to combine a super-fast OS with scratch drives and big, cheap SSDs. For my machine, I got 2 terabytes (TB) of SSD storage.

One caveat is that using the second M.2 slots can block the second PCIe expansion slot. That approach means that if you plan to add high-bandwidth PCIe cards beyond the GPU, you’ll want to plan your layout carefully.

On the connectivity front, the Mira Custom includes 2.5 Gigabit Ethernet (GbE), Wi-Fi 7, and Bluetooth 5.2. This setup provides modern wired and wireless connectivity suitable for both home lab and office environments. I connected it to both my local 2.5 GbE network and my Netgear Orbi 970-powered Wi-Fi 7 network. On either network, I saw both Internet and local network speeds of over 2 gigabits per second (Gbps).

The audio is handled by the Realtek ALC1220 codec which achieves 7.1-channel output. The front and back panels feature a mix of USB4 Type-C and multiple USB-A ports, as well as a front-facing USB for easy access for everyday use.

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Specifically, the system comes with 13 external USB ports, standard audio and network ports, and video output, which is determined by the GPU you choose. The front panel has 1 × USB 3.2 Gen2 Type-C, 2 × USB 3.2 Gen1 Type-A, and a 3.5 mm combo earphone jack. On the back, you will find 2 × USB4 Type-C, 1 × USB 3.2 Gen2 Type-A, 3 × USB 3.2 Gen1 Type-A, and 4 × USB 2.0 Type-A. That capability adds up to 10 USB ports. If, like me, you don’t believe there is such a thing as enough ports, you’ll be in heaven.

You’ll also find separate 3.5 mm line in, out, and mic-in jacks on the back. The system also comes with an S/PDIF optical out that supports up to 7.1-channel audio. For video, its integrated graphics reveal 1 × HDMI 2.1 output and 2 × USB4/DisplayPort-over-USB-C ports. The Nvidia card reveals 3 × DisplayPort outputs and 1 × HDMI 2.1 output.

Look and feel

System76’s language of “industrial precision” isn’t just marketing. The tower chassis is a combination of aluminum and steel with a milled front I/O bar, tempered glass side panel, and tool-free magnetic panels that make access to fans, radiators, and cabling a breeze. That approach makes developing the program easier.

The front-facing ports and bottom dust filter address two long-standing annoyances of previous Thelio generations: poor front I/O and tedious cleaning.

The entire foot of this tower is compact. Every cubic inch is clearly allocated to air flow, cable routing, and future upgrades instead of good looks. That said, one good machine.

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Another plus for some users, as System76 founder and CEO Carl Richell told me recently, is that the company builds its systems at its factory in Denver, Colorado. There, the company says, its servers, desktops, and laptops are “Designed by geniuses. Designed by professionals. Designed by people.”

Richell describes Mira as “the beginning of that renaissance of new desktop design,” a platform that allows System76 to relearn the power of heat, architecture, and scale. System76 put the chassis through adhesive testing and mechanical stress — robots pulling the side and front panels thousands of times — to ensure the new modular construction will withstand years of use and field service.

The results are amazing. This system is the best-looking workstation I’ve used since the early 1990s, when I had the pleasure of using the Silicon Graphics (SGI) IRIS Indigo and NEXTStation Turbo Color.

The price

Custom Configuration is exactly what it sounds like: you choose the CPU, RAM, storage, and GPU, which determines the price. The price range starts at “extreme but affordable” $1,699 and enters the “this is my main workstation for years” $7,000-plus territory. My system listed around $6,500. If I were a serious programmer, AI developer, or professional gamer, I would happily pay the money. As a tech journalist, I can’t justify money, but I wish I could. This is one fun program.

System76 also offers pre-configured Premium and Elite variants of Mira. However, a Custom SKU is where Linux power users and developers can customize a machine for farm integration, critical development work, home labs, or local AI rigs without having to pay for different parts.

You pay a clear premium for DIY, but your money buys integration, thermals, and support from a vendor whose entire stack, from firmware to operating system, is geared towards Linux.

ZDNET shopping advice

For people like me, who are tired of cutting their fingers putting together their systems, the new System76 for 2026 Thelio Mira Custom desktop PC it’s a win. Sure, I could save a few hundred bucks by building and fixing the parts myself. However, I have never put together such a beautiful Linux workstation that combines high-end AMD and Nvidia hardware with good looks and cooling aimed equally at continuous, demanding tasks.

In short, this is the best Linux workstation I have ever seen. If that’s what you need, this is the computer you want to buy.