Results of latency test, list of computers tested for use with LinuxCNC

uugp
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28 Aug 2024 08:55 #308881 by uugp

Replied by uugp on topic Results of latency test, list of computers tested for use with LinuxCNC

seuchato wrote:
uugp
Nice find! Those values are very good, almost too good to be true! If however those values are true and at 9000 there are no random latency issues anymore, then you do have a very nice system for software stepping, too.
Kindly allow a couple of questions / remarks / recommendations:

Did you run any other program? I see 10 glxgears, but what about a browser, vimeo or youtube, ... while doing the latency test?

On board graphics is usually the way to go. Tracking down and elimination sparce spikes is a hard job, usually also with questionable success. So I'd stick with onboard graphics.

What do you mean by "... and obtain a good color ..."?

Seems the mobo is for Athlon IIX* cpus, which appeared around 2009. So, really old . I'd check the capacitors before making chips and/or have a spare one available. Not sure if such an old mobo is really a good idea as a cnc controller though.

Greez
chris

Hi seuchato

Sorry for the late reply.
1.YES! If this can runwith10 glxgears, then running other programs will be run fine.But I'm just using it as a controller, no programs unrelated to the controller will run during operation. Gcode transmitted over Samba.
2.YES! Many failed experimental results have been placed under the desk. The purpose of posting is to avoid repeating a tedious testing task.
3.The built-in graphics card is weak and only provides a dim desktop color. Opening an app will also cause blinking, although running LCNC is fine. So I am also hesitant about whether to use an external graphics card.
4.Checking the capacitance is necessary. Usually no problem. If you are lucky, you can buy brand new antiques. As long as it works, it's good, no matter whether it's new or old. A 40-nanometer chip can last for 20 years, exceeding the limit of mechanical wear and tear.
I've been encountering all kinds of weird problems with the new PC, I just haven't posted them.

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webbyguy
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14 Mar 2025 13:48 #323926 by webbyguy

Replied by webbyguy on topic Results of latency test, list of computers tested for use with LinuxCNC

Hi shellcrash,
I'm trying to get an X6 1090T working with a biostar A880GZ motherboard (which I think is just one generation newer). I'm so far unable to get as low a jitter as you got, and I was wondering if you remembered any bios, kernel, etc settings that enabled you to get such low jitter numbers.

I've only gotten below 40us jitter so far: forum.linuxcnc.org/38-general-linuxcnc-q...it-of-jitter?start=0

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workshop54
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28 May 2025 08:08 #329294 by workshop54

Replied by workshop54 on topic Results of latency test, list of computers tested for use with LinuxCNC

I just did the latency test on a Fitlet3 after making some changes to the BIOS and running the script from forum.linuxcnc.org/38-general-linuxcnc-q...ead-and-irq-affinity

LinuxCNC pc tests, version 20200930, started 28.05.2025 09:37:54
********************************************************************************
General info:
Compulab,  fitlet3
Bios version FLT3.TPM.00.09, dated 06/08/2024
Chipset: Harddisk is non-rotational, ie. SSD
The amount of swap currently used is 0
================================================================================
CPU related data:
model name    : Intel Atom(R) x6425E Processor @ 2.00GHz
cpu cores    : 4
stepping    : 1
cache size    : 4096 KB
================================================================================
RAM related data:
Maximum Capacity: 16 GB
Maximum Voltage: 1.2 V
Size: 8 GB
Non-Volatile Size: None
Volatile Size: 8 GB
Cache Size: None
Logical Size: None
Size: No Module Installed
================================================================================
GPU related data:
product: Elkhart Lake [UHD Graphics Gen11 32EU]
configuration: depth=32 driver=i915 latency=0 mode=1920x1200 resolution=1920,1200 visual=truecolor xres=1920 yres=1200
================================================================================
Parallel port related data:
number of parallel ports is 0
================================================================================
Os and desktop related data:
PRETTY_NAME="Debian GNU/Linux 12 (bookworm)"

Should the info below not match with your machine,
kindly post the output of pstree here, including a brief
desciption of your desktop environment, window manager and
display manager. Tia
https://forum.linuxcnc.org/18-computer/39370-script-for-automated-testing-of-computer-latency

Desktop environment : lightdm
Windowmanager       : Xfwm4
Displaymanager      : lightdm
================================================================================
Kernel related data:
Kernel 6.1.0-35-rt-amd64
GRUB_CMDLINE_LINUX_DEFAULT="quiet intel_idle.max_cstate=0 idle=poll isolcpus=3 nohz_full=3 rcu_nocbs=3 i915.enable_rc6=0"
Cpu idle driver: none
================================================================================
Kernel modules data:
Check if pcspkr is loaded: No, which is good!
Check if snd modules are loaded: No, which is good!
================================================================================
Keyboard & Mouse related data:
Number of mice: 1
Mouse 0 : Logitech Trackball
Mice  attached to USB:
Keyboards attached to USB:
Logitech, Inc. Keyboard K120
================================================================================
LinuxCNC related data:
LinuxCNC version is: 2.9.4
================================================================================
Preparing for latency test:
Started glxgears No. 1, 2, 3, 4, 5
..........
Started firefox with 'https://vimeo.com/150574260', WID
================================================================================
Command for latency test is:
su johan -c  "latency-histogram --nobase  --sbinsize 1000 --nox 2>&1 | tee -a 1748417872.lat &"

Latency testing loop started Wed May 28 09:38:08 AM CEST 2025,
should end after Wed May 28 11:38:08 AM CEST 2025

Manual termination requested at 28.05.2025 09:54:18

================================================================================
Swap useage: prerun: 0, running: 0

================================================================================
CPU core temperatures:
Core 0: Tmin: 53.0°C, Tmax: 61.0°C, (high = +105.0°C, crit = +105.0°C)
Core 1: Tmin: 53.0°C, Tmax: 61.0°C, (high = +105.0°C, crit = +105.0°C)
Core 2: Tmin: 52.0°C, Tmax: 61.0°C, (high = +105.0°C, crit = +105.0°C)
Core 3: Tmin: 52.0°C, Tmax: 61.0°C, (high = +105.0°C, crit = +105.0°C)
================================================================================
last latency data is as follows:.

The final output of the latency test:

^C
Stand by and let me stop gracefully...
 

Manual termination requested at 28.05.2025 09:54:18
  970 s  servo min:-409.600 us max: 404.900 us sdev:  15.700 us
  971 s  servo min:-409.600 us max: 404.900 us sdev:  15.700 us
Core 0:        +59.0°C  (high = +105.0°C, crit = +105.0°C)
Core 1:        +59.0°C  (high = +105.0°C, crit = +105.0°C)
Core 2:        +59.0°C  (high = +105.0°C, crit = +105.0°C)
Core 3:        +59.0°C  (high = +105.0°C, crit = +105.0°C)
Cleaning up
terminated latency-test ...
...........
Closing browser firefox with WID of
There are no windows in the stack
Invalid window '%1'
Usage: windowactivate [options] [window=%1]
--sync    - only exit once the window is active (is visible + active)
If no window is given, %1 is used. See WINDOW STACK in xdotool(1)
Done.
..........
================================================================================
Swap useage: prerun: 0, running: 0

================================================================================
CPU core temperatures:
Core 0: Tmin: 53.0°C, Tmax: 61.0°C, (high = +105.0°C, crit = +105.0°C)
Core 1: Tmin: 53.0°C, Tmax: 61.0°C, (high = +105.0°C, crit = +105.0°C)
Core 2: Tmin: 52.0°C, Tmax: 61.0°C, (high = +105.0°C, crit = +105.0°C)
Core 3: Tmin: 52.0°C, Tmax: 61.0°C, (high = +105.0°C, crit = +105.0°C)
================================================================================
last latency data is as follows:.

Hardware info is logged here: 1748417872.hw.
Full latency-test data is logged here: 1748417872.lat.


Kindly place the contents of "1748417872.hw" here:
https://forum.linuxcnc.org/18-computer/39371-results-of-latency-test-list-of-computers-tested-for-use-with-linuxcnc

Thanks, and good bye.

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