linuxcnc Latency test ambiguous results

 
 
 
   
I have run various tests with different commands to check the latency but I don't know if I'm doing things correctly:

with stress I get good results with all the cpus at maximum usage, instead with chrt even if the cpus are not busy I see disastrous latency.
what should I do (kernel parameters, kernel recompilation)? the PC is not good for LinuxCNC?
If I don't use hardware parallel port and use NVEM, does this latency matter for operation?

my hardware:
motherboard: P8H61/USB3 R2.0
CPU: Intel(R) Core(TM) i5-3470 CPU @ 3.20GHz
VGA: VGA compatible controller: NVIDIA Corporation GF119 [GeForce GT 610] (rev a1) (Driver NOUVEAU)
Controller: NVEM V5

What was the result of the ping command?
 

PCW wrote:

What was the result of the ping command?

 

You need result of all 40000000?

No, just the statistics reported at the end of:

ping -c 4 -i .2 10.10.10.10
sudo chrt 99 ping -i .001 -q -c  60000 10.10.10.10

The last command will run for 1 minute


 

ping -c 4 -i .2 10.10.10.10
PING 10.10.10.10 (10.10.10.10) 56(84) bytes of data.
64 bytes from 10.10.10.10: icmp_seq=1 ttl=255 time=0.295 ms
64 bytes from 10.10.10.10: icmp_seq=2 ttl=255 time=0.416 ms
64 bytes from 10.10.10.10: icmp_seq=3 ttl=255 time=0.278 ms
64 bytes from 10.10.10.10: icmp_seq=4 ttl=255 time=0.425 ms

--- 10.10.10.10 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 612ms
rtt min/avg/max/mdev = 0.278/0.353/0.425/0.067 ms


chrt 99 ping -i .001 -q -c 60000 10.10.10.10
PING 10.10.10.10 (10.10.10.10) 56(84) bytes of data.

--- 10.10.10.10 ping statistics ---
60000 packets transmitted, 59999 received, 0.00166667% packet loss, time 60751ms
rtt min/avg/max/mdev = 0.158/0.255/4.918/0.225 ms

rtt min/avg/max/mdev = 0.158/0.255/4.918/0.225 ms

Yeah, ~ 5 ms will be an issue

What is the Ethernet hardware?

If Realtek you likely need to install the DKMS driver

I need search and compile him or only apt-get?

There are some instructions here:

forum.linuxcnc.org/9-installing-linuxcnc...dware-eg-realtek-nic
 

I have a nvidia 610 video card, should I replace nouveau with the proprietary nvidia driver? (I already did it in theory)

I don't think the video is an issue as it would show up in the generic latency tests.