LinuxCNC compatible industrial PC

Hi everyone,I’ve been looking for a suitable new industrial PC for LinuxCNC with Mesa (Ethernet-connected, 7i94), but the search is becoming frustrating.

There’s a lot of great information out there, but most recommendations point to older refurbished systems that are either no longer available here (Europe) or require a lot of BIOS tuning to get acceptable latency. I’d really prefer to avoid spending a lot of time testing different systems or diving deep into BIOS settings and latency tuning.

I’m already spending enough time figuring out the electrics, HAL setup, Python interface, and machine logic — so I’m really hoping to just buy one thing that works reliably and doesn’t add another rabbit hole to the project.

What I’m looking for is a currently available, new industrial PC that:

• Works reliably with LinuxCNC (using the preempt-rt kernel)
• Is known to perform well with Mesa over Ethernet (7i94)
• Doesn’t require deep tweaking to get good performance
• Is ideally fanless or low-noise and compact (DIN mountable is a plus, but not required)

Budget isn’t my biggest concern — I don’t mind spending a bit more if it helps me avoid hours of frustration and trial-and-error.

If anyone has experience with a specific model (e.g., something from OnLogic, Beckhoff, or Fitlet2-type devices) that works well without surprises, I’d really appreciate a recommendation.

Thanks!

Not a specific recommendation, but in general I would suggest
hardware with a Intel rather than RealTek Ethernet interface
(as this avoids the needed DKMS driver installation with RealTek
and newer kernels)

Used "Enterprise" edition PC's worked for me always, The likes of older Dell, newish HP and Lenovo and Fujitsu.
And, yes i have several "industrial" PC's collecting dust in the shop, they are just plain PC in a strange box and with much higher price.

there are a number of industrial PC's on Alibaba/Aliexpress.
Echoing PCW's comments about Intel NIC. I would look for 2 NIC's but you might get more
Probably external Wifi SMA connectors. This lets you extend antennas outside of your enclosure
Also, look for a built in serial port or two for VFD etc. Some have native RS485 ports with screw terminals builtin.
They usually come with a Vesa mounting bracket to mount behind a monitor so it should be easy to mount on a DIN rail. Meanwell have a nice aluminium bracket.

Hi all, I’m planning to use a Compulab Fitlet3 as the controller PC for a LinuxCNC setup (Mesa 7i94T over Ethernet). My goal is a quiet, compact, low-latency machine with dual LAN and enough performance for a Qt UI (e.g., QtDragon or ProbeBasic), without excessive overhead. Here’s the configuration I’m considering:  

Fitlet3 configuration: 

• CPU: Intel Atom x6425E (4 cores @ 2.0 GHz base, 3.0 GHz burst, 12 W TDP)
• RAM: 8 GB DDR4 SODIMM
• Storage: 256 GB NVMe (M.2 Key-M)
• No SATA drive, no WiFi or modem
• Audio: Analog audio codec module
• I/O: Terminal block with RS-232/RS-485/GPIO
• Enclosure: Standard finned top cover (rated for 18 W)
• Thermal spec: Extended range –20°C to +70°C
• TPM: Not installed
• FACET card: FC3-LAN (adds 2× Intel i210/i225 Gbit LAN)

I plan to run the official LinuxCNC ISO with Preempt-RT, not a custom kernel or patched distro. Hence, I’m relying on the FC3-LAN FACET card for known-good Intel NICs, as the onboard Marvell NICs require kernel 5.15+ and I’d prefer to avoid that complexity.  

My questions: 

1. Has anyone here run LinuxCNC with a Fitlet3 (or similar Elkhart Lake system)?
2. Is the x6425E predictable and stable under Preempt-RT with Mesa boards over Ethernet?
3. Can anyone confirm that the following BIOS options are present and can be disabled in a AMI Inc. BIOS? 
   • Intel Turbo Boost
   • CPU C-states
   • SpeedStep (EIST)
   • CPU power management (set to Performance)

I’d also appreciate any pointers on edge cases I might be overlooking, or real-world latency results on this hardware (if available). 

Thanks in advance — I’d love to avoid going down a rabbit hole if this platform has hidden caveats. 

Quiet PC will mean nothing in a workshop.
I've never been a fan of the Atom platform, those small form factor PC's run hot, even just sitting in an open room my industrial PC running pfsense needs a reboot every day or so in summer.
Your mileage may vary but just be aware of the heat issue.
If you want dual NICs in a small form factor I'd choose an Odroid H4 and just bung it in the CNC enclosure, my H3 has never given a issue, even when running in the Australian summer.