Problem moving from a 5i25+7I76 to a 7i76E.

The second ping command should have printed statistics
when it finished, like:

99 ping -i .001 -q 10.10.10.10
[sudo] password for pcw:           
PING 10.10.10.10 (10.10.10.10) 56(84) bytes of data.
^C
--- 10.10.10.10 ping statistics ---
2934 packets transmitted, 2934 received, 0% packet loss, time 2932ms
rtt min/avg/max/mdev = 0.072/0.082/0.102/0.005 ms

But the initial ping is really terrible with nearly 1 ms ping times so that is the issue

Maybe there are some driver settinge that need adjusting
What does

ethtool [your_ethernet_device_name]

report?

and what do

ethtool --show-eee [your_ethernet_device_name]

and

ethtool --show-coalesce [your_ethernet_device_name]

report?

 

I ran the second ping again and left it for about a minute.
PING 10.10.10.10 (10.10.10.10) 56(84) bytes of data.
^C
--- 10.10.10.10 ping statistics ---
251616 packets transmitted, 251615 received, 0.000397431% packet loss, time 252221ms
rtt min/avg/max/mdev = 0.058/0.466/12.643/0.049 ms, pipe 2

Settings for enp3s0:
Supported ports: [ TP MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
2500baseT/Full
Supported pause frame use: Symmetric Receive-only
Supports auto-negotiation: Yes
Supported FEC modes: Not reported
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
2500baseT/Full
Advertised pause frame use: Symmetric Receive-only
Advertised auto-negotiation: Yes
Advertised FEC modes: Not reported
Link partner advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Link partner advertised pause frame use: Symmetric
Link partner advertised auto-negotiation: Yes
Link partner advertised FEC modes: Not reported
Speed: 100Mb/s
Duplex: Full
Auto-negotiation: on
master-slave cfg: preferred slave
master-slave status: slave
Port: Twisted Pair
PHYAD: 0
Transceiver: external
MDI-X: Unknown
Supports Wake-on: pumbg
Wake-on: d
Link detected: yes

john@X3CNC:~$ sudo ethtool --show-coalesce enp3s0
netlink error: Operation not supported

This time I haven't yet installed the r8125-dkms driver. Should I install that and give this stuff another try?

Yikes 12.643 ms! and dropped packets...

Doesn't sound very promising

You might try the driver or maybe there an issue with your RT kernel

Did you run a normal latency test?

I have run the test on this hardware. These were the last numbers in the .lat file.

7203 s servo min: -86.500 us max: 86.200 us sdev: 4.600 us
7203 s servo min: -86.500 us max: 86.200 us sdev: 4.600 us
7204 s servo min: -86.500 us max: 86.200 us sdev: 4.600 us

I had run the histogram yesterday for a few hours. The outer edges were around -50 & 50. I will run both again today.

Should I be stressing the machine while the histogram is running? I ran it both ways yesterday and didn't notice a significant difference.

I also see that if you save the screen as screen shot in the default location they get deleted at reboot.

Thanks
John

So kernel latency seems OK So maybe a a badly broken driver
If the latest Ethernet driver doesn't work it may be that that Ethernet
MAC is simply not suitable for real time.

I gave both the pings a try with a different cable

4 bytes from 10.10.10.10: icmp_seq=1 ttl=64 time=0.357 ms
64 bytes from 10.10.10.10: icmp_seq=2 ttl=64 time=0.371 ms
64 bytes from 10.10.10.10: icmp_seq=3 ttl=64 time=0.369 ms
64 bytes from 10.10.10.10: icmp_seq=4 ttl=64 time=0.353 ms

john@X3CNC:~$ sudo chrt 99 ping -i .001 -q 10.10.10.10
PING 10.10.10.10 (10.10.10.10) 56(84) bytes of data.
^C
--- 10.10.10.10 ping statistics ---
14687 packets transmitted, 14687 received, 0% packet loss, time 14719ms
rtt min/avg/max/mdev = 0.304/0.337/3.494/0.036 ms

I would  stay with axis until you get your PC up and running. Some errors are from qtpvcp or something.

Re the odroid. 

can you try installing the r8125-dkms drivers

sudo apt install dkms
sudo apt install -y linux-headers-$(uname -r)
sudo apt install r8125-dkms

Reboot and repeat the ping tests.
You might need to explore to see what driver gets installed...

It is possible on a newer PC with Secure boot/uefi that it won't like dkms as it changes stuff at the kernel level
You need to create a key for dkms. You may need to research this

I tried the driver once before but I am going to try it again. As far as Axis, I have been using QTDragon for a couple of years and I would rather switch back to my old hardware and 2.8.4 than go back to using Axis. My main goal was to switch to QTDragon_HD. I'm not getting as good latency as I was getting in previous testing. I'm going to focus on getting regular latency and network latency to respectable numbers and then proceed with getting LCNC to run.

Thanks
John