Thanks for your reply, That was my intend to write such a small routine that will sample the CPU and automatically tune the various options in order to achieve something reasonable for the user and machine.
May be a bit off topic, but what do you mean exactly by "minimising cache misses"? There is no disk access during calculation phase (which is multithreaded). Thanks Philippe LELONG Le 26-04-2014 16:17, Sean Harmer a écrit : > On Saturday 26 April 2014 11:24:52 mai...@virtual-winds.org wrote: >> Hello, >> >> I have an application which can be very cpu-intensive, depending on >> some >> options that play on the precision of computation (you can't expect >> the >> same precision in the same time on an Android phone or a multi-core >> latest cpu generation desktop). >> >> Ideally, I would like the application to tune automatically these >> options based on the ranking of the machine cpu-wise, let's say >> "slow", >> "normal", "fast". >> >> I will probably write my own small cpuTest routine, but I was >> wondering >> if there is something in Qt that could return such a benchmarking >> result? > > How about allocating a time budget of x milliseconds then timing how > long your > calculations take for precision = n. If it's too slow, reduce n. If it > has > time to spare increase n. QElapsedTimer can help here. > > If your algorithm can be parallelised then you may want to consider > using >1 > worker thread to distribute the work. > > For such tight computations also check your data layout to minimise > cache > misses. This can make a world of difference. > > Cheers, > > Sean > > -- > Dr Sean Harmer | sean.har...@kdab.com | Managing Director UK > Klarälvdalens Datakonsult AB, a KDAB Group company > Tel. Sweden (HQ) +46-563-540090, USA +1-866-777-KDAB(5322) > KDAB - Qt Experts - Platform-independent software solutions > _______________________________________________ > Interest mailing list > Interest@qt-project.org > http://lists.qt-project.org/mailman/listinfo/interest _______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
