Finally figured out all the necessary kernel flags to get jitter below 20k. I thought the PC was trash initially because it was over 1M with BIOS settings disabled, but I fixed it after reading the forums and the documentation. Contrary to common practice, I currently have all the power/performance features enabled in BIOS with the kernel flags preventing power saving or bad behavior. The script was modified since old AMD AM2 motherboards report CPU temperature, not Core temperature, and I replaced the output from /etc/default/grub to the 2nd line from dmesg.
Code:
LinuxCNC pc tests, version 20200930, started 15.04.2022 08:49:29
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General info:
ASUSTeK Computer INC., System Product Name
Bios version 2801, dated 08/23/2010
Chipset: Harddisk is rotational
The amount of swap currently used is 0
================================================================================
CPU related data:
model name : Quad-Core AMD Opteron(tm) Processor 1354
cpu cores : 4
stepping : 3
cache size : 512 KB
================================================================================
RAM related data:
Maximum Capacity: 8 GB
Size: 2048 MB
Size: No Module Installed
Size: 2048 MB
Size: No Module Installed
================================================================================
GPU related data:
product: RS780C [Radeon 3100]
configuration: driver=radeon latency=0
================================================================================
Parallel port related data:
number of parallel ports is 1
parport0: PC-style at 0x378, irq 7 [PCSPP,TRISTATE]
================================================================================
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
https://forum.linuxcnc.org/18-computer/39370-script-for-automated-testing-of-computer-latency
Desktop environment : gnome
Windowmanager : Metacity (Marco)
Displaymanager : lightdm
================================================================================
Kernel related data:
Kernel 4.19.195-rtai-amd64
[ 0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-4.19.195-rtai-amd64 root=UUID=4073631f-841a-4052-937d-db13e0ebdbd0 ro idle=poll isolcpus=3 irqaffinity=1,2
Cpu idle driver: ================================================================================
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: 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 : USB Optical Mouse
Mice attached to USB:
Avago Technologies, Pte. ADNS-5700 Optical Mouse Controller (3-button)
Keyboards attached to USB:
Lite-On Technology Corp. Keyboard
================================================================================
LinuxCNC related data:
LinuxCNC version is: 2.8.2
================================================================================
Preparing for latency test:
Started glxgears No. 1, 2, 3, 4, 5
..........
Started firefox with 'https://vimeo.com/150574260', WID 58720259
================================================================================
Command for latency test is:
su fifi -c "latency-histogram --bbinsize 1000 --base 25000 --sbinsize 1000 --nox 2>&1 | tee -a 1650026966.lat &"
Latency testing loop started Fri 15 Apr 2022 08:49:44 AM EDT,
should end after Fri 15 Apr 2022 10:49:44 AM EDT
================================================================================
Swap useage: prerun: 0, running: 0
================================================================================
CPU temperatures:
CPU 0: Tmin: 60.0°C, Tmax: 64.0°C, (high = +60.0°C, crit = +95.0°C)
================================================================================
last latency data is as follows:.
7205 secs base min: -18.100 uS max: 18.700 uS sdev: 0.300 uS
7205 secs servo min: -13.400 uS max: 13.600 uS sdev: 0.300 uS
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