[Python-Dev] Python 3.0.1 (io-in-c) (original) (raw)

Scott David Daniels Scott.Daniels at Acm.Org
Wed Jan 28 08:05:32 CET 2009

Raymond Hettinger wrote:

[Antoine Pitrou] Now here are some performance figures. Text I/O is done in utf-8 with universal newlines enabled: That's a substantial boost. How does it compare to Py2.x equivalents?

Comparison of three cases (including performance rations): MB/S MB/S MB/S in C in py3k in 2.7 C/3k 2.7/3k ** Binary append ** 10M write 1e6 units at a time 1529.00 728.000 1523.000 2.10 2.09 20K write one unit at a time 0.668 0.150 0.887 4.45 5.91 400K write 20 units at a time 12.200 2.880 15.800 4.24 5.49 400K write 4096 units at a time 722.00 346.000 1071.000 2.09 3.10 ** Binary input ** 10M read whole contents at once 980.00 274.000 966.000 3.58 3.53 20K read whole contents at once 924.00 443.000 1145.000 2.09 2.58 400K alternate read & seek 1000 units 490.000 81.200 563.000 6.03 6.93 400K alternate read & seek one unit 1.330 0.082 1.11 16.20 13.52 400K read 20 units at a time 27.200 3.440 29.200 7.91 8.49 400K read 4096 units at a time 845.00 246.000 1038.000 3.43 4.22 400K read one unit at a time 1.64 0.174 1.480 9.43 8.51 400K read whole contents at once 883.00 216.000 891.000 4.09 4.13 400K seek forward 1000 units a time 516.00 182.000 568.000 2.84 3.12 400K seek forward one unit at a time 0.528 0.188 0.893 2.81 4.75 ** Binary overwrite ** 20K modify one unit at a time 0.677 0.123 0.867 5.50 7.05 400K alternate read & write 1000 unit 276.000 41.100 153.000 6.72 3.72 400K alternate read & write one unit 0.827 0.045 0.22 18.46 4.93 400K alternate write & seek 1000 unit 173.000 71.400 151.000 2.42 2.11 400K alternate write & seek one unit 0.212 0.082 0.237 2.60 2.90 400K modify 20 units at a time 12.100 2.340 15.300 5.17 6.54 400K modify 4096 units at a time 382.00 213.000 446.000 1.79 2.09 ** Text append ** 10M write 1e6 units at a time 261.00 218.000 1540.000 1.20 7.06 20K write one unit at a time 0.983 0.081 1.33 12.08 16.34 400K write 20 units at a time 16.000 1.510 22.90 10.60 15.17 400K write 4096 units at a time 236.00 118.000 1244.000 2.00 10.54 ** Text input ** 10M read whole contents at once 89.700 68.700 966.000 1.31 14.06 20K read whole contents at once 108.000 70.500 1196.000 1.53 16.96 400K read 20 units at a time 29.200 3.800 28.400 7.68 7.47 400K read 4096 units at a time 97.400 34.900 1060.000 2.79 30.37 400K read one line at a time 71.700 3.690 207.00 19.43 56.10 400K read one unit at a time 2.280 0.218 1.41 10.46 6.47 400K read whole contents at once 112.000 81.000 841.000 1.38 10.38 400K seek forward 1000 units at a time 87.400 67.300 589.000 1.30 8.75 400K seek forward one unit at a time 0.090 0.071 0.873 1.28 12.31 ** Text overwrite ** 20K modify one unit at a time 0.296 0.072 1.320 4.09 18.26 400K modify 20 units at a time 5.690 1.360 22.500 4.18 16.54 400K modify 4096 units at a time 151.000 88.300 509.000 1.71 5.76

--Scott David Daniels Scott.Daniels at Acm.Org

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