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

If you've to spend money anyway you could better spend it on a Mesa card or Remora compatible device. With a hardware stepgen the 60-80 uS is ok. Otherwise there is a topic about the Orange Pi 5 which has a very low latency, Guglielmi has made a HAL component for the GPIO which he will release after has tested it.

You could try some kernel parameters to improve the latency if you want to, you can find several in this thread.

But this thread is actually to show your results. for questions it might be better to start a new topic.

Thank you for that info,
I couldn’t find how low the latency is ?

Very interesting board.

Results from my ODroid H2+

latency-histogram results with the same kernel currently in the Gentoo for LinuxCNC build (v0.2-alpha) 

This really looks veeeerry nice!
greez
chris

MB  GA-J1800N-D2H(BIOS F6)
RAM KVR13S9S8/4 4Gb
SSD SA400S37/240G
Debian 10 Buster 4.19.0-17-amd64, linuxcnc-2.8.4-buster.iso, without any updates.
LinuxCNC v. 2.10 rip build

kernel parameters: "isolcpus=1 intel_idle.max_cstate=0 processor.max_cstate=0 idle=poll quiet"
 

Looking good !

HP PRODESK 800 G4 SFF
i5 6500K
32GB RAM (big latency improvement)
2.5" SSD
ATI Radeon HD 6000 (big latency improvement)
6.1.0-13-rt-amd64
LINUXCNC 2.9.1
GRUB_CMDLINE_LINUX_DEFAULT="quiet isolcpus=2,3 intel_idle.max_cstate=0 processor.max_cstate=0 idle=poll"

I have several industrial boards and thin clients and did a quick test on the new 2.9.1 from the download section site. All systems had 4GB of memory each, all power saving features were turned off in the bios.  


2 different boards on J1900:


On one of the systems on the J1800 I did 2 tests, one default with a live install from a flash drive, the other with the system installed and kernel parameters isolcpus=1
 
 
Not very good values, but I think for mesa all these boards will be enough, but for LPT.....

Try without the base thread/period
latency-histogram --nobase --sbinsize 1000 --show