On Tue, Apr 8, 2014 at 11:00 PM, big stone <stonebi...@gmail.com> wrote: > Hi, > > I did experiment splitting my workload in 4 threads on my cpu i3-350m to > see what are the scaling possibilities. > > Timing : > 1 cpu = 28 seconds > 2 cpu = 16 seconds > 3 cpu = 15 seconds > 4 cpu = 14 seconds >
If the info at http://ark.intel.com/products/43529/Intel-Core-i3-350M-Processor-3M-Cache-2_26-GHz is right, you have 2 cores, each having 2 threads. They're logically "cores", but physically not so. My tests with any multi-threading benchmarking including parallel quicksort showed that a similar i3 mobile processor rarely benefit after 2 threads, probably cache coherence penalty is the cause. Desktop Intel Core i5-2310, for example, is a different beast (4 cores/4 threads), 3 threads almost always was x3 times faster, 4 threads - with a little drop. It all still depends on the application. Once I stopped believing a 2-threaded Atom would show x2 in any of tests I made, when on one graphical one it finally made it. But still if number of threads are bigger than number of cores then it's probably a legacy of HyperThreading hardware Intel started multi-threading with Max _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
