Ashish Kulkarni wrote: > Hello, > > R version 2.4.1 (2006-12-18) > i386-pc-mingw32 > > Calling serialize() with a NULL connection serializes it to a raw vector. > However, when the object to be serialized is large, it takes a very long time: > >> system.time( serialize(matrix(0, 1000, 1000), NULL) ) > [1] 38.25 40.73 81.54 NA NA > >> system.time( serialize(matrix(0, 2000, 2000), NULL) ) > [1] 609.72 664.75 1318.57 NA NA
<snipped> >> system.time( .mpi.quick.serialize(matrix(0, 1000, 1000) ) ) > [1] 0.2500000000000000 0.0499999999999545 0.3000000000001819 > [4] NA NA > >> system.time( .mpi.quick.serialize(matrix(0, 2000, 2000) ) ) > [1] 1.059999999999945 0.220000000000027 1.289999999999964 > [4] NA NA > > Does anyone have an idea why the performance difference is so > large? Also, I was wondering if there is a better way -- the > above solution feels like a quick fix rather than a correct > approach. It might be interesting to know get some details on your hardware. On my box, linux native seems to be a little slower than your quick.serialize times: > system.time( serialize(matrix(0, 1000, 1000), NULL) ) [1] 0.372 0.288 0.692 0.000 0.000 > system.time( serialize(matrix(0, 2000, 2000), NULL) ) [1] 1.237 1.195 2.501 0.000 0.000 running R 2.4.1 windows under wine (same box) is a good deal s lower, but is not anywhere nearly as slow as yours. > system.time( serialize(matrix(0, 1000, 1000), NULL) ) [1] 0.00 0.00 6.08 NA NA > system.time( serialize(matrix(0, 2000, 2000), NULL) ) [1] 0.01 0.01 78.00 NA NA > Since you mentioned that you are using Rmpi, there is a possibility that you might be calling a different serialize() than base::serialize all together??? ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
