Did you run the identical code on the identical machine, and did you verify there were no other tasks running which might have limited the RAM available to R? And equally important, did you run these tests in the reverse order (in case R was storing large objects from the first run, thus chewing up RAM)?
Dear All, is it known that source works much faster in R 2.15.2 than in R 3.0.2 ? In the example below I observe e.g. for a data.frame with 10^7 rows the following timings: R version 2.15.2 Patched (2012-11-29 r61184) length: 1e+07 user system elapsed 62.04 0.22 62.26 R version 3.0.2 Patched (2013-10-27 r64116) length: 1e+07 user system elapsed 388.63 176.42 566.41 Is there a way to speed R version 3.0.2 up to the performance of R version 2.15.2? best regards, Heinz Tüchler example: sessionInfo() sample.vec <- c('source', 'causes', 'R', 'to', 'accept', 'its', 'input', 'from', 'the', 'named', 'file', 'or', 'URL', 'or', 'connection') dmp.size <- c(10^(1:7)) set.seed(37) for(i in dmp.size) { df0 <- data.frame(x=sample(sample.vec, i, replace=TRUE)) dump('df0', file='testdump') cat('length:', i, '\n') print(system.time(source('testdump', keep.source = FALSE, encoding=''))) } output for R version 2.15.2 Patched (2012-11-29 r61184): > sessionInfo() R version 2.15.2 Patched (2012-11-29 r61184) Platform: x86_64-w64-mingw32/x64 (64-bit) locale: [1] LC_COLLATE=German_Switzerland.1252 LC_CTYPE=German_Switzerland.1252 [3] LC_MONETARY=German_Switzerland.1252 LC_NUMERIC=C [5] LC_TIME=German_Switzerland.1252 attached base packages: [1] stats graphics grDevices utils datasets methods base > sample.vec <- + c('source', 'causes', 'R', 'to', 'accept', 'its', 'input', 'from', 'the', + 'named', 'file', 'or', 'URL', 'or', 'connection') > dmp.size <- c(10^(1:7)) > set.seed(37) > > for(i in dmp.size) { + df0 <- data.frame(x=sample(sample.vec, i, replace=TRUE)) + dump('df0', file='testdump') + cat('length:', i, '\n') + print(system.time(source('testdump', keep.source = FALSE, + encoding=''))) + } length: 10 user system elapsed 0 0 0 length: 100 user system elapsed 0 0 0 length: 1000 user system elapsed 0 0 0 length: 10000 user system elapsed 0.02 0.00 0.01 length: 1e+05 user system elapsed 0.21 0.00 0.20 length: 1e+06 user system elapsed 4.47 0.04 4.51 length: 1e+07 user system elapsed 62.04 0.22 62.26 > output for R version 3.0.2 Patched (2013-10-27 r64116): > sessionInfo() R version 3.0.2 Patched (2013-10-27 r64116) Platform: x86_64-w64-mingw32/x64 (64-bit) locale: [1] LC_COLLATE=German_Switzerland.1252 LC_CTYPE=German_Switzerland.1252 [3] LC_MONETARY=German_Switzerland.1252 LC_NUMERIC=C [5] LC_TIME=German_Switzerland.1252 attached base packages: [1] stats graphics grDevices utils datasets methods base > sample.vec <- + c('source', 'causes', 'R', 'to', 'accept', 'its', 'input', 'from', 'the', + 'named', 'file', 'or', 'URL', 'or', 'connection') > dmp.size <- c(10^(1:7)) > set.seed(37) > > for(i in dmp.size) { + df0 <- data.frame(x=sample(sample.vec, i, replace=TRUE)) + dump('df0', file='testdump') + cat('length:', i, '\n') + print(system.time(source('testdump', keep.source = FALSE, + encoding=''))) + } length: 10 user system elapsed 0 0 0 length: 100 user system elapsed 0 0 0 length: 1000 user system elapsed 0 0 0 length: 10000 user system elapsed 0.01 0.00 0.01 length: 1e+05 user system elapsed 0.36 0.06 0.42 length: 1e+06 user system elapsed 6.02 1.86 7.88 length: 1e+07 user system elapsed 388.63 176.42 566.41 > -- View this message in context: http://r.789695.n4.nabble.com/big-speed-difference-in-source-btw-R-2-15-2-and-R-3-0-2-tp4679314p4679346.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.