On Sat, Mar 15, 2008 at 9:26 PM, Matthew Smith <[EMAIL PROTECTED]> wrote: > My first choice is my Sun Blade 100 as it is small, quiet, doesn't use...
last time I looked at a dmesg from one of those, it looked just like my old hp laptop... but an ultrasparc cpu. > unless OpenBSD happens to have support for add-on USB PCI cards. it does. i had an old machine with USB1.1 only. $10 at the computer shop got me some super-cheap 2-port USB2 controller with an NEC chip on it. worked like a charm. uou may have problems booting off an add-on USB card... maybe the bios/firmware is smart enough to do that, maybe not. once the kernel takes over you should be good to go. > The potential problem with the Blade is that it has absolutely lousy > timekeeping. If run without NTPD, it will drift minutes out in a day. > I am advised that this is a hardware issue specific to that model. I > believe that there is a patch to compensate for this in Solaris, but > it's seriously bad under Linux. it's a pee-cee - of course its clock is lousy. solaris probably compensates for this the same way openbsd would: calculate a frequency correction over time, and adjust your clock frequency based on that. let a userland program adjtime() fairly frequently to keep the clock very close to right on. if nothing else, can we get you to try it for a week and document just how awful it is? (more than 5000ppm?) > The question is this - does it matter? If I am running NTPD and feeding > in NMEA+PPS, is the native timekeeping (or lack of) an issue? running on just the bog-standard crystal, my soekris seems to keep time to within a few microseconds - i got similar results with 3 sunfire v120's. i think that's about as good as it gets without expending serious effort to redo all the interrupt handling. adjtime() gets called every 3 minutes or so to pull in those last few microseconds, and a reasonable first guess at a frequency correction will happen within 25 minutes. it'll take about 75 minutes for ntpd to decide how to adjust those last few fractions of a ppm. CK -- GDB has a 'break' feature; why doesn't it have 'fix' too? _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
