RTAPI error and realtime delay at EMC launch

I use Sheetcam for plasma. Looks like the Linux version is behind the Windoze one by 1.

John

hcb wrote:

Servo thread max jitter: 273915
Base thread max jitter: 113919

That's horrible latency. But do you know when in the test it happened? If there is a spike soon after boot and then it doesn't repeat then you might have a borderline-usable system, but otherwise those numbers make the machine (in its current configuration) a non-starter.

You could try experimenting with your own custom kernel builds.

Cool, thank you. That looks cheap enough (110 pounds...maybe 150-170 US). I'll give it a go when I get my CNC plasma table built.

--HC

Andy, that occurred long after the system was booted. I had the system booted and had logged in to this site to read your and John's posts and had already started then terminated the latency test once (as listed in a previous post by me at the time I did it) and then, after doing a test of setting the latency to 40k as you requested, I restarted the Latency Test. I let it run since that day (5 maybe 7 days). The screensaver would have kicked on a few times (Matrix), I have done some random web searches when I was closer to this system than any of my others, and that's it. It was way past boot time when I started the test.

I know nothing about building custom kernels. I think the system has some weird anomaly and I don't know what to do next. I've tried all kinds of changes to the BIOS to turn things off or tweak settings and no luck.

It's not a big deal. It would have been nice to be able to use this system but if not, I have a couple of other computers I can try. If all else fails, John posted some good results with that Intel Atom board so I'll build one.

I appreciate the help and time. I don't like to give up on a problem but this has gotten to the point that it's more trouble than it's worth.

--HC

Fortunately SheetCam has a try before you buy plan and I recommend this to start.

Dry disabling the screen saver, on one computer this gave me a horrible spike in latency.

Also read this

wiki.linuxcnc.org/cgi-bin/emcinfo.pl?FixingSMIIssues

John

Thank you, John. I will do the try before you buy when the time comes (I'm still designing the gantry for the plasma table).

I had gotten a link to that page from Andy and had tried to disable SMI but got the message:

error inserting (path to rtai_smi.ko): -1 No such device 2641

Searching for that message online (google.com) gave me few results (including a couple of links to this thread) and nothing that seemed relevant to my problem (inexact matches for parts of the search string which finally was: error inserting (path to rtai_smi.ko).

Gonna move to the next Linux fodder...I've got a Dell that gave me some trouble (going to go back and see what it was...I forget now)...then I have an HP Pavilion with a P4 and one with a Celeron. If I don't get one that will work (or I get bored playing with this stuff) I'll build a system based on the board you liked and have had good results with.

As for the screensaver, I could disable it but the instructions for the Latency Test said to "abuse the machine" so I thought that would have been a good test since I don't have GLXGears.

Thanks again.

--HC