On Sun 01 Oct 2023 at 13:39:17 (+0000), Andrew M.A. Cater wrote: > On Sun, Oct 01, 2023 at 08:58:36AM -0400, Greg Wooledge wrote: > > On Sun, Oct 01, 2023 at 05:07:48AM -0400, gene heskett wrote: > > > You've a good view of this hw. However swap is not important to run > > > linuxcnc, in fact its to be avoided because it messes with realtime > > > response. Linuxcnc needs, even with much of the control offloaded to mesa > > > and similar smart cards, it still needs to check what the machine is doing > > > 1000 times a second. The way I'm doing it, the wobble in this timing as 50 > > > to 80 microseconds, which doesn't bother the machine all that much, the > > > real > > > time killer is firing up firefox which can lock out the irq response for > > > hundreds of milliseconds. So I don't carve metal and browse the web at > > > the > > > same time. > > > > If Firefox is really just for "browsing the web", and is not part of > > the user interface for the CNC pieces, I don't understand why you run > > Firefox on this machine at all. I would run the browser on a separate > > computer, one which isn't so critical to your operation. > > > Echoing Greg: > > 2G is a fairly small amount of memory - by default the *Debian* install > for RPi 4 now gives you 1G of swap on whatever medium - which you should > never need to use. > > It would make sense for something real time critical to be on a 2GB or 4GB RPi > on it's own - if you're running modellers or whatever for 3D printing, that > might be different but a command line or simplest web interface might be > best. You REALLY don't want anything extraneous. > > Pi 4GB or 8GB are now available more or less: your BananaPi - you are *very* > much on your own.
Back in 2018, Gene's explanation was: https://lists.debian.org/debian-user/2018/11/msg00049.html Cheers, David.
