error finishing read!

I have installed LinuxCNC on 3 computers so far. 
1) Laptop i7: Very good latency times, very poor ping times - > unusable
2) Esprimo Q956 Mini PC with i5: poor latency, good ping - > unusable
3) DELL Optiplex 7010 Mini PC with Intel Celeron G2030 (by far the weakest processor): good latency, good ping (see appendix) -> usable
 
So the worst of the 3 processors is the best for real-time Linux in terms of latency and ping!!!???
So it must also be due to the mainboard, possibly the memory, ... !?

sunny greetings

 

Most common cause of really terrible network latency
(ping times > 1 ms) is power management setup

Pining the IRQ can help if you are close but if you have 4 ms ping times
the host most likely has power management/speed switching still enabled


 

Hello,
I am now trying to get LinuxCNC to run stably on my fourth computer. It didn't work at all with the first two. The third and weakest one ran reasonably well but that was only a loaner.
The new one is now a Dell OptiPlex 3050 SFF with an i7. The histogram looks quite good +-30. Unfortunately, I'm having problems with the max ping times again (see attachment).

I have filmed the BIOS and network settings and you can see them here:


Are they OK or do I need to change something there?
PCW had written the following on page 1:
"If your PC has an Intel Ethernet chip make sure you disable IRQ coalescing
(man hm2_eth)"
However, my network card (enp1s0) is not listed in the networks file (see attachment). Where should I insert the entry described in man hm2_eth?
How can I determine whether the computer uses an Intel Ethernet chi at all?

Are there any other possibilities for the origin of the high ping times?
Could it also be due to the MESA card?
Best regards






 

I would disable turbo-boost in the BIOS as anything that changes the CPU clock
can cause major latencies.

The interfaces file is an alternate way to setup a network connection.
to use it, you must add the required lines to the interfaces file, something like:

       auto enp1s0
       iface enp1s0 inet static
           address 192.168.1.120/24
           hardware-irq-coalesce-rx-usecs 0


The last line only makes sense if you have a Intel Ethernet chip

One way to check for this is:

dmesg | grep -i eth

(you may need sudo dmesg | grep -i eth on some systems

or

 lspci | grep -i eth

Also check that you have ethtool installed with:

man ethtool

or the " hardware-irq-coalesce-rx-usecs 0" line will not do anything

 

Thank you for your efforts and the quick reply.
I will test it tomorrow.
I have also just ordered a network card:
Intel Gigabit CT Desktop Adapter 893647 Network Card EXPI9301CT 
Perhaps this will work better than the onboard network card.

VG Anton

Thank you again for your support.
The problem was the onboard NIC.
After I installed a PCI NIC LinuxCNC runs stable.
VG Anton