One more thing. I also do uncached reads of a rom fixed value like address to account for the actual bus transaction time. This gives a lower bound on how fast things can go.
jerry On 10/10/2013 10:08 AM, Jerry Scharf wrote: > Hi, > > Are these 18s20s? I am used to seeing higher resolution on the > temperature from 18B20s. > > You can actually take the sleep out of there. The first read will stall > until the conversion completes and then the rest will happen at the bus > transaction speed. > > I always used the uncached directory when doing timing work, just to > make sure I am not getting cached data that would screw up the timing. > What I do is a couple runs with out simultaneous and a couple with and > look for the difference in elapsed time. > > jerry > > On 10/10/2013 09:25 AM, Håkan Elmqvist wrote: >> And here is the result for 12 DS1820: >> root@hemx:~# echo 1 >/ow/simultaneous/temperature; time (sleep 1; cat >> /ow/10.*/temperature;) >> 23.5 23.3125 23.375 23.5 23.25 23.5 >> 23.375 23.375 23.5 23.5 23.5625 23.375 >> real 0m1.944s >> user 0m0.000s >> sys 0m0.000s >> >> >> >> >> ------------------------------------------------------------------------------ >> October Webinars: Code for Performance >> Free Intel webinars can help you accelerate application performance. >> Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from >> the latest Intel processors and coprocessors. See abstracts and register > >> http://pubads.g.doubleclick.net/gampad/clk?id=60134071&iu=/4140/ostg.clktrk >> _______________________________________________ >> Owfs-developers mailing list >> Owfs-developers@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/owfs-developers > > ------------------------------------------------------------------------------ > October Webinars: Code for Performance > Free Intel webinars can help you accelerate application performance. > Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from > the latest Intel processors and coprocessors. See abstracts and register > > http://pubads.g.doubleclick.net/gampad/clk?id=60134071&iu=/4140/ostg.clktrk > _______________________________________________ > Owfs-developers mailing list > Owfs-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/owfs-developers ------------------------------------------------------------------------------ October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register > http://pubads.g.doubleclick.net/gampad/clk?id=60134071&iu=/4140/ostg.clktrk _______________________________________________ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
