Hello, Since this is measuring a short workload after vom startup it might not be the best benchmark, but then again throughput GC is expected to be faster than G1. In the particular case however I guess you could tune G1 a bit to that workload. Did you check the verbose GC logs, and how many CPUs does Java see/use?
Gruss Bernd -- http://bernd.eckenfels.net On Mon, Oct 31, 2016 at 8:38 PM +0100, "Peter" <graphhop...@gmx.de> wrote: Hi, I've stumbled today* over a big speed difference for code execution with G1 GC vs. parallel GC also in the latest JDK8 (1.8.0_111-b14). Maybe you have interests to investigate this. You should be able to reproduce this via: # setup git clone https://github.com/graphhopper/graphhopper wget http://download.geofabrik.de/europe/germany/bayern-latest.osm.pbf cd graphhopper # run measurement export JAVA_OPTS="-XX:+UseParallelGC -Xmx1000m -Xms1000m" # the graphhopper.sh script just makes the installation of maven and bundling the jar a bit simpler # you can also execute the tests in the class Measurement.java ./graphhopper.sh clean ./graphhopper.sh measurement berlin-latest.osm.pbf # now a measurement-<some date>.properties is created: grep routing.mean measurement-XY.properties Now this should print a line where the value is in ms. E.g. I get ~450ms for the parallel GC and ~780ms for G1GC (on an old laptop). When I increase the Xmx for the G1 run to 1400m the results do NOT get closer to parallel GC! Let me know if you need more information! Regards Peter * https://github.com/graphhopper/graphhopper/issues/854 -- GraphHopper.com - fast and flexible route planning
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