On Aug 8, 2012, at 2:34 PM, Rick Jones wrote: > Is that unsuitability inherent in USB, so it matters not whether there > is anything else on the USB, or is it more a case of being "bad" > generally only when other things are on the same USB? I'm still > looking to go serial, but was wondering.
The unsuitability is inherent to USB, although some of the issues are better under USB 3. USB 1/2 involves host-based polling rather than devices being able to handle device-initiated communications which create an interrupt which gets handled much more immediately. You're getting ~10ms of latency for a typical USB connection, versus something around a microsecond for an uncontested INT line (ie, serial or parallel). > Also, speaking of things considered "bad" and drifting - fudging the > LOCAL(0) is definitely frowned upon right? If I happen to have say > four servers in a location which might loose its connectivity to the > outside world I probably don't want those servers to fall-back on > LOCAL(0) right? Would configuring each to have the other three as > "peer" entities be the way to go? Folks probably never should use the LOCAL clock with a recent ntpd. By definition, if you're using it your offset is always zero: if you know it is off, updating it to the right time rather than fudging makes far more sense. Use orphan mode instead: http://support.ntp.org/bin/view/Support/OrphanMode Regards, -- -Chuck _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
