Mini PC for LinuxCNC/CPU Realtime Performance

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26 Jan 2026 11:18 #341928 by giaviv
I’d like to replace my weak HP EliteDesk G2 on which I currently run LinuxCNC. In my setup, the PC drives a Mesa 7i95t over ethernet, and displays a LinuxCNC UI on a monitor. Form factor is important since the PC is only used for LinuxCNC.I’m looking at various options for ~$800 range mini PCs, but am struggling to understand how they will perform in a realtime environment. Some of the options are:
  • Beelink EQR7, cpu: AMD Ryzen5 7535U
  • Beelink SER9 PRO+, cpu: AMD Ryzen7 H 255
  • GEEKOM GT13 Pro, cpu: Intel Core i9-13900HK
  • ASUS NUC 14 Pro, cpu: Intel Ultra 7 155H
  • MINISFORUM DeskMini UM870, cpu: AMD Ryzen 7 8745H
Could someone please help shed some light on how to evaluate whether these models will perform well running the LinuxCNC realtime environment?

Thanks!

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26 Jan 2026 12:17 - 26 Jan 2026 12:19 #341930 by 0x2102
I think best bet is to keep the G2 and try to optimize it for LinuxCNC.

1.) Disable all power saving options in the BIOS
2.) Update your grub CMD line to include: max_cstate=1 idle=poll isolcpus=(your last CPU core)
3.) Set up IRQ affinity (see below)
4.) Disable IRQ coalescing (see below)

forum.linuxcnc.org/38-general-linuxcnc-questions/47974-grub

forum.linuxcnc.org/38-general-linuxcnc-q...irq-affinity?start=0

forum.linuxcnc.org/38-general-linuxcnc-q...g-for-intel-ethernet

A newer or more modern PC can be sometimes worse and it's a bit of a gamble if it works out of the box.

Once you address 1 - 4 you are in control on how well your PC works with LinuxCNC.
Last edit: 26 Jan 2026 12:19 by 0x2102.
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26 Jan 2026 12:43 #341932 by giaviv
Thanks for the reply! I’ve done all that so I believe my G2 is optimized for LinuxCNC.

However I’m a bit limited by the low ram (8GB), low disk space and etc.

I realize newer models are risky, therefore some of the models I am looking at are far from new generation CPUs (like the Ryzen5 7535U).. Or is CPU not the only potential issue, but also things like the motherboard etc?

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26 Jan 2026 13:17 #341937 by Hakan
Many of us run systems with much lower spec CPUs, like Celeron J1900, i3-6100, N100, N150 with good result. 8GB should be plenty.

What does your latency-plot look like?

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26 Jan 2026 13:24 #341939 by tommylight
Replied by tommylight on topic Mini PC for LinuxCNC/CPU Realtime Performance

However I’m a bit limited by the low ram (8GB), low disk space and etc.

8GB should be fine, and how low is "low disk space"? Linux starts complaining only when you get under 1GB of free space, so anything above is fine.

I realize newer models are risky, therefore some of the models I am looking at are far from new generation CPUs (like the Ryzen5 7535U)..

7535U is not "far from new", it is new and still in production, Zen3 with 15W TDP, so it is a laptop CPU and this may be bad for latency, although not always.

Or is CPU not the only potential issue, but also things like the motherboard etc?

CPU's are mostly fine as they can change states and do stuff, mainboards are usually the latency killers depending on quality, BIOS implementation, power saving options, etc, etc, way to many to list here, but mostly bad/weak CPU power stage set to work at the edge and throttling the CPU to save itself from going up in smoke.
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As a general rule, i would stay away from those small PC's, they are cute and stuff, but way to limited thermally, the xxxxU versions are fine, but a 13900 ... oh hell no, it will be limited thermally to something like a good 4 core CPU when under load, and they fail but being limited will prolong their life a lot so...
There were some NUC's that were OK for LinuxCNC way back.
After all this, there is no way to know for sure if any of those will be OK, short of buying and testing.

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26 Jan 2026 19:57 #341968 by rodw

Thanks for the reply! I’ve done all that so I believe my G2 is optimized for LinuxCNC.

However I’m a bit limited by the low ram (8GB), low disk space and etc.
 

This is nonsense! 4 gb RAM is fine for LinuxCNC but it will tolerate 8gb without ill affect. Linux is more memory efficient than Windows.....
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27 Jan 2026 04:32 #341986 by NWE
I've had good success with generic fanless industrial mini-pc's in aluminum housings. One had a Celeron N5105, another had the J1900 CPU, both seemed performant for my applications. I was not running anything graphics intensive.

I tried a $90 USD UXX and a $110 MinsForum, with intel N4020 celeron CPUs, gave up on both of those. The one couldn't be configured to boot automatically when the power is switched on, both had insurmountable ethernet power-save features that interfered with ethercat.

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27 Jan 2026 05:01 - 27 Jan 2026 05:14 #341988 by NWE

However I’m a bit limited by the low ram (8GB), low disk space and etc.


 

LinuxCNC uses minimal RAM, but I could see needing lots of RAM if you were running CAD/CAM software on the machine and working with larger files. If that is the case you might want the kind of computing power you're talking about.

I am running a GMKtec M5 Plus mini-pc with a Ryzen 7 5825U cpu and 32GB RAM on Debian 13 and it works well. It is my only pc that also has Windows on it. It runs a lot cooler on linux and its little fan is quiet. Every time I boot Win11 on it I am reminded it has a noisy little fan that can really blow hot air. I never tried LinuxCNC or the realtime kernel on it. I left it at work today. Tomorrow evening I'll bring it home and post some latency tests from a LinuxCNC live boot.
Last edit: 27 Jan 2026 05:14 by NWE.
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28 Jan 2026 05:00 #342062 by NWE
Here it is. This is on a live boot without trying any latency optimization stuff. While this was running, I installed some software and ran glxgears.
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28 Jan 2026 09:33 #342067 by unknown
Replied by unknown on topic Mini PC for LinuxCNC/CPU Realtime Performance
Not a PC platform, but the RPi5 is more than capable running with a Mesa card, Ethernet or SPi......... Not something Tommy would recommend. I didn't for a while.....but things change.

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