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diff --git a/doc/html/TechNotes/Basic_perform.html b/doc/html/TechNotes/Basic_perform.html deleted file mode 100644 index 2a622fc..0000000 --- a/doc/html/TechNotes/Basic_perform.html +++ /dev/null @@ -1,75 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN"> -<html> - <head> - <title>Description of the three basic performance tools</title> - </head> - - <body> - <h1>Description of the three basic performance tools</h1> - - <h2>iopipe</h2> - <p>Times reads and writes to an HDF5 2-d dataset and compares that with - reads and writes using POSIX I/O. Reports seven measurements in - terms of CPU user time, CPU system time, elapsed time, and - bandwidth: - - -<DL> -<DD>fill raw: time it takes to memset() a buffer.</DD> -<DD> fill hdf5: time it takes to read from a dataset never written</DD> -<DD>out raw: time it takes to write using POSIX I/O</DD> -<DD>out hdf5: time it takes to write using H5Dwrite()</DD> -<DD>in raw: time it takes to read data just written using POSIX I/O</DD> -<DD>in hdf5: time it takes to H5Dread() data written with H5Dwrite()</DD> -<DD>in hdf5 partial: time it takes to H5Dread() the "center" area.</DD> -</DL> - - - <p>This is a pretty stupid performance test. It accesses the same area - of file and memory over and over and the file size is way too - small. But it is good at showing how much overhead there is in the - library itself. - - - <h2>chunk</h2> - <p>Determines how efficient the raw data cache is for various access - patterns of a chunked dataset, both reading and writing. The access - pattern is either (a) we access the entire dataset by moving a window - across and down a 2-d dataset in row-major order a full window - height and width at a time, or (b) we access part of a dataset by moving - the window diagonally from the (0,0) corner to the opposite corner - by half the window height and width at a time. The window is - measured in terms of the chunk size. - - - <p>The result is: - <br>A table written to stdout that contains the window size as a - fraction of the chunk size and the efficiencey of the cache (i.e., - number of bytes accessed by H5Dread() or H5Dwrite() divided by the - number of bytes of the dataset actually read or written by lower - layers. - - - <p>A gnuplot script and data files which can be displayed by running - gnuplot and typing the command `load "x-gnuplot"'. - - - <h2>overhead</h2> - <p>Measures the overhead used by the B-tree for indexing chunked - datasets. As data is written to a chunked dataset the B-tree - grows and its nodes get split. When a node splits one of three - ratios are used to determine how many items from the original node - go into the new left and right nodes, and these ratios affect the - total size of the B-tree in a way that depends on the order that - data is written to the dataset. - - - <p>Invoke as `overhead usage' for more information. - <hr> - <address><a href="mailto:matzke@llnl.gov">Robb Matzke</a></address> -<!-- Created: Tue Mar 17 11:13:35 EST 1998 --> -<!-- hhmts start --> -Last modified: Jun 4, 2003 -<!-- hhmts end --> - </body> -</html> |