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

I saw the thread here and bought "Optiplex 980" for $ 60.I have installed LinuxCNC 2.8.2 Debian10.It seems to have improved a little. I wish there was a better way.



Hmmm. I don't know how to attach the result.
How do you paste it in a gray window?

sou528 wrote:

I saw the thread here and bought "Optiplex 980" for $ 60.I have installed LinuxCNC 2.8.2 Debian10.It seems to have improved a little. I wish there was a better way.

LinuxCNC pc tests, version 20200930, started 09.03.2022 00:03:53
...

Desktop environment : gnome
Windowmanager       : Xfwm4
Displaymanager      : lightdm
================================================================================
Kernel related data:
Kernel 5.10.0-0.bpo.9-rt-amd64
GRUB_CMDLINE_LINUX_DEFAULT="quiet isolcpus=1"
Cpu idle driver: intel_idle
================================================================================
Kernel modules data:
Check if pcspkr is loaded: Yes, may cause bigger latency.
  can be eliminated using:
  sudo echo "install pcspkr /bin/true" >/etc/modprobe.d/pcspkr.conf
Check if snd modules are loaded: No, which is good!
================================================================================
...
================================================================================
Command for latency test is:
su linuxcnc -c  "latency-histogram --bbinsize 1000 --base 25000 --sbinsize 1000 --nox 2>&1 | tee -a 1646751829.lat &"

...

>>>Unexpected realtime delay on task 0 with period 25000<<<



[/spoiler]

Hmmm. I don't know how to attach the result.
How do you paste it in a gray window?
 

How do you paste it in a gray window? use Block quote in advanced editor ( [ quote ] and [ / quote ] without the blanks)

Further, run the test again, but increase base to say 50'000. 50'000 is actually what I am using on my 980. Also check out my GRUB_CMDLINE_LINUX_DEFAULT (dig in this thread to find the last, best one. Further,  do

sudo echo "install pcspkr /bin/true" >/etc/modprobe.d/pcspkr.conf

It made some difference on my machine. In addition check out the colored parts in your output and compare them to what I have used. Ie.

• KDE
• Kernel <5.xx
• ...

Greez

I posted these results because I think they're poor results and the script bailed early because of an unacceptable delay? This is a laptop which I know is usually a bad choice for linuxcnc. 

BUT...I've been using this setup for years with no issues whatsoever. Is it because I'm using a Mesa 7i76e over ethernet so the pc's latency doesn't really matter?

LinuxCNC pc tests, version 20200624, started 08.03.2022 08:20:54
********************************************************************************
General info:
SAMSUNG ELECTRONICS CO., LTD., QX310/QX410/QX510/SF310/SF410/SF510
Bios version 03MX.M005.20101011.SCY, dated 10/11/2010
Chipset: Intel Corporation 5 Series/3400 Series
Harddisk is non-rotational, ie. SSD
The amount of swap currently used is 0
================================================================================
CPU related data:
model name : Intel(R) Core(TM) i5 CPU M 480 @ 2.67GHz
cpu cores : 2
stepping : 5
cache size : 3072 KB
================================================================================
RAM related data:
Maximum Capacity: 8 GB
Size: 4096 MB
Size: 4096 MB
================================================================================
GPU related data:
product: GT218M [GeForce 310M]
product: Core Processor Integrated Graphics Controller
configuration: driver=nouveau latency=0
configuration: driver=i915 latency=0
================================================================================
Os related data:
PRETTY_NAME="Linux Mint 18.1"
Desktop: , Session:
================================================================================
Kernel related data:
Kernel 4.8.11-rt7
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
Cpu idle driver: intel_idle
================================================================================
Kernel modules data:
Check if pcspkr is loaded: No, good!
Yes, may cause bigger latency.
Check if snd modules are loaded: snd_hda_codec_hdmi 45056 1
snd_hda_codec_realtek 86016 1
snd_hda_codec_generic 73728 1 snd_hda_codec_realtek
snd_hda_intel 40960 3
snd_hda_codec 135168 4 snd_hda_intel,snd_hda_codec_hdmi,snd_hda_codec_generic,snd_hda_codec_realtek
snd_hda_core 86016 5 snd_hda_intel,snd_hda_codec,snd_hda_codec_hdmi,snd_hda_codec_generic,snd_hda_codec_realtek
snd_hwdep 16384 1 snd_hda_codec
snd_pcm 110592 4 snd_hda_intel,snd_hda_codec,snd_hda_core,snd_hda_codec_hdmi
snd_seq_midi 16384 0
snd_seq_midi_event 16384 1 snd_seq_midi
snd_rawmidi 32768 1 snd_seq_midi
snd_seq 69632 2 snd_seq_midi_event,snd_seq_midi
snd_seq_device 16384 3 snd_seq,snd_rawmidi,snd_seq_midi
snd_timer 32768 2 snd_seq,snd_pcm
snd 86016 17 snd_hda_intel,snd_hwdep,snd_seq,snd_hda_codec,snd_timer,snd_rawmidi,snd_hda_codec_hdmi,snd_hda_codec_generic,snd_seq_device,snd_hda_codec_realtek,snd_pcm
soundcore 16384 1 snd
Yes, may cause bigger latency.
================================================================================
Keyboard & Mouse related data:
Number of mice: 2
Mouse 0 : ETPS/2 Elantech Touchpad
Mouse 1 : Logitech M525
Mice attached to USB:
Keyboards attached to USB:
LinuxCNC related data:
LinuxCNC version is: 2.8.0~pre1
================================================================================
Preparing for latency test:
Started glxgears No. 1
Started glxgears No. 2
Started glxgears No. 3
Started glxgears No. 4
Started glxgears No. 5
..........
Started firefox with 'vimeo.com/150574260'

================================================================================
Command for latency test is:
su dave -c "latency-histogram --bbinsize 1000 --base 25000 --sbinsize 1000 --nox 2>&1 | tee 1646756410.lat &"

Latency testing loop started Tue Mar 8 08:21:09 PST 2022,
should end after Tue Mar 8 10:21:09 PST 2022

Unexpected realtime delay on task 0 with period 25000
should end after Tue Mar 8 10:21:09 PST 2022

Swap useage: prerun: 0, running: 0

================================================================================
last latency data is as follows:.
9 secs base min: -24.600 uS max: 56.000 uS sdev: 1.100 uS
9 secs servo min: -23.200 uS max: 24.000 uS sdev: 1.300 uS

tripwire
"usually" laptops are not good. BUT if it worked for you, it worked.
My own experience with some laptops are not nice. Given the fact, that cnc machines do stuff, that if gone wrong, can do real harm, I not going to use a controlling pc that >might< not be fit for the job. And then: why use a Laptop in a workshop to control potentially dangerous machines at all? The machines are big usually. If the controlling pc is stored away from liquids, dirty hands, chips, I think that is a good idea. Thus I usually put the controlling pc into a reach, with a door, that keeps it safe. How do you do that with a laptop, if you want to se its screen and keyboard?
To be honest: I have an old Z61p in my workshop. but it is seated far from any cnc machine. I use it to play music and do internet stuff on it.
Just my thoughts, no offense meant.

If you want the script to run through, increase base thread to 100'000 or even 200'000 and servo to a higher value too. Should you want to get better latency values, block speaker and sound modules, work with "GRUB_CMDLINE_LINUX_DEFAULT" parameters.

Greez
chris

Hello, these are the results of my tests with a 7i80 card and a nuc i3. apart from the high latency it is usable and I cut some pieces without problems except that just turned on the 7i80 is not detected and you have to remove the 5 volts and put them back to reset it. I wanted to try an old i7 to see if it was pc problem but with much better latency it is not usable. I attach histogram i3 and i7 and screenshot of the error in qtplasmac. regards Mauro

billykid
Thanks for bringuing this nuc here.  I am getting intel nucs to test in about a month or two too only. I believe, a run with less than 3 minutes is rather short. also, it would be nice, if you could post the results of my script here. Just the .hw file is enough.
Regarding mesa problem, I think you might find answers or help in other threads.
greez chris

I am trying the script, it works but the video does not start "video not rated" I let it go like this?

This is i7, i3 nuc i do later

billykid
Thanks a ton. I need to upgrade the script urgently and your zip helps me doing just that. I intended to do a complete update, but like that, I think I'll release an intermediate version soon.

I'll post what you have included in your zip as a summary, completed with last latency data:

LinuxCNC pc tests, version 20200930, started 10.03.2022 08:59:06
********************************************************************************
General info:
ASUSTeK COMPUTER INC.,  All Series
Bios version 2601, dated 12/08/2014
Chipset: Intel Corporation 9 Series
Harddisk is non-rotational, ie. SSD
The amount of swap currently used is 0
================================================================================
CPU related data:
model name    : Intel(R) Core(TM) i7-4790K CPU @ 4.00GHz
cpu cores    : 4
stepping    : 3
cache size    : 8192 KB
================================================================================
RAM related data:
Maximum Capacity: 32 GB
Maximum Voltage: Unknown
Maximum Voltage: 1.5 V
Maximum Voltage: Unknown
Maximum Voltage: 1.5 V
Size: No Module Installed
Size: 8192 MB
Size: No Module Installed
Size: 8192 MB
================================================================================
GPU related data:
product: Xeon E3-1200 v3/4th Gen Core Processor Integrated Graphics Controller
configuration: driver=i915 latency=0
================================================================================
Parallel port related data:
number of parallel ports is 0
================================================================================
Os and desktop related data:
PRETTY_NAME="Debian GNU/Linux 10 (buster)"

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
forum.linuxcnc.org/18-computer/39370-scr...-of-computer-latency

Desktop environment : gnome
Windowmanager       : Xfwm4
Displaymanager      : lightdm
================================================================================
Kernel related data:
Kernel 4.19.0-19-rt-amd64
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
Cpu idle driver: intel_idle
================================================================================
Kernel modules data:
Check if pcspkr is loaded: No, which is good!
Check if snd modules are loaded: Yes, may cause bigger latency.
  can probably be disabled in bios, alternatively, you can run
   "./block-snd-modules"
   which has just now been created for your convenience.
================================================================================
Keyboard & Mouse related data:
Number of mice: 1
Mouse 0 : Logitech USB Optical Mouse
Mice  attached to USB:
Logitech, Inc. M105 Optical Mouse
Keyboards attached to USB:
Primax Electronics, Ltd HP PR1101U / Primax PMX-KPR1101U Keyboard
================================================================================
LinuxCNC related data:
LinuxCNC version is: 2.9.0~pre0.5982.gcebd57f65
================================================================================
Preparing for latency test:
Started glxgears No. 1, 2, 3, 4, 5
..........
Started firefox with 'vimeo.com/150574260', WID 88080428
================================================================================
Command for latency test is:
su mauro -c  "latency-histogram --nobase  --sbinsize 1000 --nox 2>&1 | tee -a 1646899127.lat &"

Latency testing loop started gio 10 mar 2022, 08.59.18, CET,
should end after gio 10 mar 2022, 10.59.18, CET

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

================================================================================
CPU core temperatures:
Core 0: Tmin: 28.0°C, Tmax: 56.0°C, (high = +80.0°C, crit = +100.0°C)
Core 1: Tmin: 27.0°C, Tmax: 60.0°C, (high = +80.0°C, crit = +100.0°C)
Core 2: Tmin: 28.0°C, Tmax: 58.0°C, (high = +80.0°C, crit = +100.0°C)
Core 3: Tmin: 24.0°C, Tmax: 55.0°C, (high = +80.0°C, crit = +100.0°C)
================================================================================
last latency data is as follows:.


7202 s servo min: -30.400 us max: 30.300 us sdev: 0.700 us

That seems to be a very good candiate, given, you still got room to improve. But I guess, tommlight would agree: good as it is now, no further improvments required. One caveat: The video stuff: Couldn't you see the vimeo video at all?
Greez
chris

I think the advice has made a big step forward. I haven't tried KERNEL yet.

LinuxCNC pc tests, version 20200930, started 10.03.2022 02:10:07
********************************************************************************
General info:
Dell Inc.,  OptiPlex 980                 
Bios version A18, dated 02/27/2018
Chipset: Intel Corporation 5 Series/3400 Series
Harddisk is non-rotational, ie. SSD
The amount of swap currently used is 0
================================================================================
CPU related data:
model name    : Intel(R) Core(TM) i5 CPU         650  @ 3.20GHz
cpu cores    : 2
stepping    : 5
cache size    : 4096 KB
================================================================================
RAM related data:
Maximum Capacity: 16 GB
Size: 2048 MB
Size: 2048 MB
Size: 2048 MB
Size: 2048 MB
================================================================================
GPU related data:
product: Core Processor Integrated Graphics Controller
configuration: driver=i915 latency=0
================================================================================
Parallel port related data:
number of parallel ports is 1
parport0: PC-style at 0x378 (0x778), irq 7 [PCSPP,TRISTATE,EPP]
================================================================================
Os and desktop related data:
PRETTY_NAME="Debian GNU/Linux 10 (buster)"

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
forum.linuxcnc.org/18-computer/39370-scr...-of-computer-latency

Desktop environment : kdeconnectd
Windowmanager       : KWin
Displaymanager      : lightdm
================================================================================
Kernel related data:
Kernel 4.19.0-19-rt-amd64
GRUB_CMDLINE_LINUX_DEFAULT="quiet isolcpus=1 mitigations=off intel_idle.max_cstate=0 processor.max_cstate=0 idle=poll acpi_irq_nobalance noirqbalance"
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: 2
Mouse 0 : CATEX TECH. 84EC-S Mouse
Mouse 1 : Logitech M570
Mice  attached to USB:
Keyboards attached to USB:
================================================================================
LinuxCNC related data:
LinuxCNC version is: 2.8.2.11.g6a3d0a434
================================================================================
Preparing for latency test:
Started glxgears No. 1, 2, 3, 4, 5
..........
Started firefox with 'vimeo.com/150574260', WID 71303372
================================================================================
Command for latency test is:
su optiplex980 -c  "latency-histogram --bbinsize 1000 --base 25000 --sbinsize 1000 --nox 2>&1 | tee -a 1646845802.lat &"

Latency testing loop started 2022年  3月 10日 木曜日 02:10:21 JST,
should end after 2022年  3月 10日 木曜日 04:10:21 JST

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

================================================================================
CPU core temperatures:
Core 0: Tmin: 53.0°C, Tmax: 63.0°C, (high = +89.0°C, crit = +105.0°C)
Core 2: Tmin: 53.0°C, Tmax: 61.0°C, (high = +89.0°C, crit = +105.0°C)
================================================================================
last latency data is as follows:.
 7204 secs   base min: -18.300 uS max:  15.500 uS sdev:   0.200 uS
 7204 secs  servo min: -12.300 uS max:  12.300 uS sdev:   0.500 uS

LinuxCNC pc tests, version 20200930, started 10.03.2022 08:49:32
********************************************************************************
General info:
Dell Inc.,  OptiPlex 980                 
Bios version A18, dated 02/27/2018
Chipset: Intel Corporation 5 Series/3400 Series
Harddisk is non-rotational, ie. SSD
The amount of swap currently used is 0
================================================================================
CPU related data:
model name    : Intel(R) Core(TM) i5 CPU         650  @ 3.20GHz
cpu cores    : 2
stepping    : 5
cache size    : 4096 KB
================================================================================
RAM related data:
Maximum Capacity: 16 GB
Size: 2048 MB
Size: 2048 MB
Size: 2048 MB
Size: 2048 MB
================================================================================
GPU related data:
product: Core Processor Integrated Graphics Controller
configuration: driver=i915 latency=0
================================================================================
Parallel port related data:
number of parallel ports is 1
parport0: PC-style at 0x378 (0x778), irq 7 [PCSPP,TRISTATE,EPP]
================================================================================
Os and desktop related data:
PRETTY_NAME="Debian GNU/Linux 10 (buster)"

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
forum.linuxcnc.org/18-computer/39370-scr...-of-computer-latency

Desktop environment : kdeconnectd
Windowmanager       : KWin
Displaymanager      : lightdm
================================================================================
Kernel related data:
Kernel 4.19.0-19-rt-amd64
GRUB_CMDLINE_LINUX_DEFAULT="quiet isolcpus=1 mitigations=off intel_idle.max_cstate=0 processor.max_cstate=0 idle=poll acpi_irq_nobalance noirqbalance"
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: 2
Mouse 0 : CATEX TECH. 84EC-S Mouse
Mouse 1 : Logitech M570
Mice  attached to USB:
Keyboards attached to USB:
================================================================================
LinuxCNC related data:
LinuxCNC version is: 2.8.2.11.g6a3d0a434
================================================================================
Preparing for latency test:
Started glxgears No. 1, 2, 3, 4, 5
..........
Started firefox with 'vimeo.com/150574260', WID 71303422
================================================================================
Command for latency test is:
su optiplex980 -c  "latency-histogram --bbinsize 1000 --base 50000 --sbinsize 1000 --nox 2>&1 | tee -a 1646869745.lat &"

Latency testing loop started 2022年  3月 10日 木曜日 08:49:45 JST,
should end after 2022年  3月 10日 木曜日 10:49:45 JST

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

================================================================================
CPU core temperatures:
Core 0: Tmin: 50.0°C, Tmax: 62.0°C, (high = +89.0°C, crit = +105.0°C)
Core 2: Tmin: 51.0°C, Tmax: 60.0°C, (high = +89.0°C, crit = +105.0°C)
================================================================================
last latency data is as follows:.
 7202 secs   base min: -19.200 uS max:  17.300 uS sdev:   0.300 uS
 7202 secs  servo min: -15.400 uS max:  14.800 uS sdev:   0.600 uS

Thank you for teaching me how to write.