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I profiled our Grib code (2.2.18) and found a bottleneck in some of the low-level routines such as Grib1BinaryDataSection.bits2UInt(), ucar.unidata.io.RandomAccessFile.read(), and, to a lesser degree, in ucar.grib.GribNumbers.float4(). Has the UCar team ever thought of moving to Java NIO? I rewrote the ucar.grib.GribNumbers.float4() method in NIO and got 10 fold performance boost. I will post the new float4() if anyone is interested. As far as RandomAccessFile.read(), the reason our program was spending so much time in it was because of a multiplier inside the Grib1BinaryDataSection constructor. So 2,558 calls to the Grib1BinaryDataSection constructor resulted in 273,175,727 calls to RandomAccessFile.read()! Is there anything I can do about that? Increase the defaultBufferSize size? It looks as if we have it set to 8K, but I was thinking of increasing that substantially. Can I do this without a recompile? Frederick Thurber GDIT Middletown, RI
netcdf-java
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