From be3b47d0d504a3409ce66bd77bb8c0acff87c4f5 Mon Sep 17 00:00:00 2001 From: kh1 Date: Thu, 15 Mar 2012 14:53:47 +0100 Subject: Reorganize the tree, have better ifw.pri. Shadow build support. Change-Id: I01fb12537f863ed0744979973c7e4153889cc5cb Reviewed-by: Tim Jenssen --- src/libs/7zip/unix/DOCS/MANUAL/commands/bench.htm | 79 +++++++++++++++++++++++ 1 file changed, 79 insertions(+) create mode 100644 src/libs/7zip/unix/DOCS/MANUAL/commands/bench.htm (limited to 'src/libs/7zip/unix/DOCS/MANUAL/commands/bench.htm') diff --git a/src/libs/7zip/unix/DOCS/MANUAL/commands/bench.htm b/src/libs/7zip/unix/DOCS/MANUAL/commands/bench.htm new file mode 100644 index 000000000..14f456cd3 --- /dev/null +++ b/src/libs/7zip/unix/DOCS/MANUAL/commands/bench.htm @@ -0,0 +1,79 @@ + + + + + b (Benchmark) command + + + + + +

b (Benchmark) command

+ +

Measures speed of the CPU and checks RAM for errors.

+ +

Syntax

+ +
+b [number_of_iterations] [-mmt{N}] [-md{N}] [-mm={Method}]
+
+ +

There are two tests:

+

    +
  1. Compressing with LZMA method +
  2. Decompressing with LZMA method +
+ +

The benchmark shows a rating in MIPS (million instructions per second). +The rating value is calculated from the measured CPU speed and it +is normalized with results of Intel Core 2 CPU with multi-threading option +switched off. So if you have Intel Core 2 Duo, +rating values must be close to real CPU frequency.

+ +

You can change the upper dictionary size to increase memory usage by -md{N} switch. +Also, you can change the number of threads by -mmt{N} switch.

+ +

The Dict column shows dictionary size. For example, 21 means 2^21 = 2 MB.

+ +

The Usage column shows the percentage of time the processor is working. +It's normalized for a one-thread load. For example, 180% CPU Usage for 2 threads +can mean that average CPU usage is about 90% for each thread.

+ +

The R / U column shows the rating normalized for 100% of CPU usage. +That column shows the performance of one average CPU thread.

+ +

Avr shows averages for different dictionary sizes.

+

Tot shows averages of the compression and decompression ratings.

+ +

Compression speed and rating strongly depend on memory (RAM) latency. + +

Decompression speed and rating strongly depend on the integer performance of the CPU. +For example, the Intel Pentium 4 has big branch +misprediction penalty (which is an effect of its long pipeline) and pretty slow +multiply and shift operations. So, the Pentium 4 has pretty low decompressing ratings.

+ +

You can run a CRC calculation benchmark by specifying -mm=crc. +That test shows the speed of CRC calculation in MB/s. The first column shows the size of the block. +The next column shows the speed of CRC calculation for one thread. The other columns are results +for multi-threaded CRC calculation.

+ + +

Examples

+ +
+7z b
+
+runs benchmarking. + +
+7z b -mmt1 -md26
+
+runs benchmarking with one thread and 64 MB dictionary. + +
+7z b 30
+
+

runs benchmarking with default settings for 30 iterations.

+ + + -- cgit v1.2.3