+1 one that ! It's really hard to pick good hardware .... unless you buy & try !
Cheers ! / Lars 2013/5/6 Kent A. Reed <[email protected]>: > On 5/6/2013 9:16 AM, Lars Segerlund wrote: >> check the data on osadl.org ... with RT-Preempt you should be able to >> get worstcase jitters of less than 50 us ... or you have a 'bad' >> system / bad drivers. >> >> With a 'good' RT-Preempt system you get < 20 us as worstcase. >> >> osadl is good since they are really hammering the systems while measuring. >> >> / regards, Lars Segerlund. >> > > Lars: > > I'm not looking to open a discussion about the definition of jitter and > the appropriate methodology for measuring it (we've had some of those in > the past on this list, and some of us are quite familiar with OSADL). > > What I'm looking for is better guidance to our CNC users, most of whom > find the details about latency as understandable as details about the > fuel-injection algorithm used in their car's computer. What we have seen > in the time I've been reading the emc2- lists amounts to constant > schoolyard taunting, "my latency is better than your latency." Look how > excited we get when the latest Atom board yields 1us lower or higher > jitter results than another. If the better guidance includes pointing to > the OSADL as another source of data (along with suggestions on how to > interpret those data) so much the better for the folks who wish to use > RT-PREEMPT enabled kernels (and my thanks to those on this list who have > been making it possible for the average user to even consider using them). > > Regards, > Kent > > > ------------------------------------------------------------------------------ > Introducing AppDynamics Lite, a free troubleshooting tool for Java/.NET > Get 100% visibility into your production application - at no cost. > Code-level diagnostics for performance bottlenecks with <2% overhead > Download for free and get started troubleshooting in minutes. > http://p.sf.net/sfu/appdyn_d2d_ap1 > _______________________________________________ > Emc-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-developers ------------------------------------------------------------------------------ Introducing AppDynamics Lite, a free troubleshooting tool for Java/.NET Get 100% visibility into your production application - at no cost. Code-level diagnostics for performance bottlenecks with <2% overhead Download for free and get started troubleshooting in minutes. http://p.sf.net/sfu/appdyn_d2d_ap1 _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
