Question about latency

I was just testing latency on my new setup and found that I get better latency when running a base thread than I do without. I realize that both numbers are good considering I am using Mesa cards.

What are the pros and cons of running a base thread and not running one?

The only complaint I have about the machine is that the UI is sluggish on everything except LinuxCNC. If I run the halmeter it is hard to navigate scroll and select the pin to watch. Moving a browser on the screen causes all of the glxgears to stop and it doesn't move smoothly. Below is my setup and results.

Linux Mint 19.2 running the RTAI kernel and LinuxCNC 2.8.0~Pre1 on a ECS BAT-I j1800 montherboard with 4gb RAM, Mesa 5i25(6i25) + 7i76 + 7i83.

Linux X3CNC 4.14.148-rtai-amd64 #2 SMP PREEMPT Sat Nov 9 16:29:10 GMT 2019 x86_64 x86_64 x86_64 GNU/Linux





Thanks John

If you are using hardware stepping, a base thread will just waste CPU resources, as long as you
don't have more than a few 100 usec latency there is no real advantage to reducing the latency

Thanks PCW. I am using hardware stepping. I was just curios. I did the same test in Linux Mint 19.3 and got similar results.

You will also see this effect if you increase the servo thread rate
I suspect it is a caching side effect ( a higher thread rate means its less likely
for real time bits of LinuxCNC to be evicted from the cache )