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Home modified by Vladimir Ryabtsev

Vladimir Ryabtsev — Wed, 03 Dec 2014 10:30:59 -0000

--- v13
+++ v14
@@ -72,7 +72,7 @@
 It's due to caching. Files are written into OS memory cache and the program is informed that write operation finished thus it stops watch. Small file can be written in "zero" time. But actually data is not written to disk completely.
 Memory cache is not unlimited. We can overfull it to get more accurate results. When cache is full OS has no choice and it dumps data to disk. The larger file you create the more accurate reults you get. Try to make write test with increasing file size – when speed stops to decrease the real device speed is reached.
 File written persists in cache until it extruded by other data. This means that even though file has been completely written to disk read request may get it from cache again. Remember about it when performing combined write and read test in file mode (`-w` and `-r` options). The file that has just been written is read again from cache, at least partially. Also remember about it when you use `-nodel` option to create large file. You should create large enough file to extrude beginning of it from cache.
-In drive mode caching is also performed, but the utility chooses a random position on disk before reading, thus reducing a chance to meet cached area to minimum.
+In drive mode caching is also performed, but the utility chooses a random position on disk before reading, thus reducing a chance to meet the cached area to minimum.

 ## Memory
 Program performs simple memory-to-memory copying. Two blocks of `size` MB are copied to each other `rounds` times. The result is shown in MB/s. Remember that this result depends on not only physical memory speed but also on processor.

Home modified by Vladimir Ryabtsev

Vladimir Ryabtsev — Wed, 03 Dec 2014 10:14:20 -0000

--- v12
+++ v13
@@ -41,7 +41,7 @@

      -h, /?     This help

-PerfTest launched with no parameters is equivalent to `PerfTest -w -r -s -cpu -mem`
+PerfTest launched with no parameters is equivalent to `PerfTest -r -s -cpu -mem`

 ## Disk speed

Home modified by Vladimir Ryabtsev

Vladimir Ryabtsev — Wed, 03 Dec 2014 10:13:38 -0000

--- v11
+++ v12
@@ -2,7 +2,7 @@

 ## Basics
 This utility measures throughput of main hardware components: disks, CPU and memory as it seen from application running on current computer. Standard operating system calls are used for read/write access to memory and disks. The results shown should not be compared to results of other performance testing utilities which can use special modes for memory and disk access, but you can compare the test results of this utility from different computers, or the results from the same computer under different conditions.
-This utility was initially designed to perform basic automated tests on virtual machines where lack of resource problems could suddenly occur.
+This utility was initially designed to perform basic automated tests on virtual machines where problems  of lack of resources could suddenly occur.

 ## Syntax
 The utility shows its syntax on `/?` and '-h' options.

Home modified by Vladimir Ryabtsev

Vladimir Ryabtsev — Wed, 03 Dec 2014 00:05:52 -0000

--- v10
+++ v11
@@ -80,6 +80,6 @@
 ## CPU
 Some set of calculations in integer and floating point arithmetics is performed. The set is called "complex operation" (CO) and is performed `cycles` times. Utility forces all CPU cores load to 100%. The result is shown in CO/s.

-Se also [Running on Virtual Machines]
+Se also [Running PerfTest on Virtual Machines]

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Home modified by Vladimir Ryabtsev

Vladimir Ryabtsev — Wed, 03 Dec 2014 00:01:56 -0000

--- v9
+++ v10
@@ -80,4 +80,6 @@
 ## CPU
 Some set of calculations in integer and floating point arithmetics is performed. The set is called "complex operation" (CO) and is performed `cycles` times. Utility forces all CPU cores load to 100%. The result is shown in CO/s.

+Se also [Running on Virtual Machines]
+
 [[download_button]]

Home modified by Vladimir Ryabtsev

Vladimir Ryabtsev — Tue, 02 Dec 2014 14:37:02 -0000

--- v8
+++ v9
@@ -78,6 +78,6 @@
 Program performs simple memory-to-memory copying. Two blocks of `size` MB are copied to each other `rounds` times. The result is shown in MB/s. Remember that this result depends on not only physical memory speed but also on processor.

 ## CPU
-Some set of calculations in integer and floating point arithmetics is performed. The set is called "complex operation" (CO) and is performed `cycles` times. The result is shown in CO/s.
+Some set of calculations in integer and floating point arithmetics is performed. The set is called "complex operation" (CO) and is performed `cycles` times. Utility forces all CPU cores load to 100%. The result is shown in CO/s.

 [[download_button]]

Home modified by Vladimir Ryabtsev

Vladimir Ryabtsev — Mon, 01 Dec 2014 16:09:54 -0000

--- v7
+++ v8
@@ -75,7 +75,7 @@
 In drive mode caching is also performed, but the utility chooses a random position on disk before reading, thus reducing a chance to meet cached area to minimum.

 ## Memory
-Program performs simple memory-to-memory copying. Two blocks of `size` MB are copied to each other `rounds` times. The result is shown in MB/s. Remember that this result depends on not only physical memory spead but also on processor.
+Program performs simple memory-to-memory copying. Two blocks of `size` MB are copied to each other `rounds` times. The result is shown in MB/s. Remember that this result depends on not only physical memory speed but also on processor.

 ## CPU
 Some set of calculations in integer and floating point arithmetics is performed. The set is called "complex operation" (CO) and is performed `cycles` times. The result is shown in CO/s.

Home modified by Vladimir Ryabtsev

Vladimir Ryabtsev — Mon, 01 Dec 2014 16:09:06 -0000

--- v6
+++ v7
@@ -2,6 +2,7 @@

 ## Basics
 This utility measures throughput of main hardware components: disks, CPU and memory as it seen from application running on current computer. Standard operating system calls are used for read/write access to memory and disks. The results shown should not be compared to results of other performance testing utilities which can use special modes for memory and disk access, but you can compare the test results of this utility from different computers, or the results from the same computer under different conditions.
+This utility was initially designed to perform basic automated tests on virtual machines where lack of resource problems could suddenly occur.

 ## Syntax
 The utility shows its syntax on `/?` and '-h' options.
@@ -74,7 +75,7 @@
 In drive mode caching is also performed, but the utility chooses a random position on disk before reading, thus reducing a chance to meet cached area to minimum.

 ## Memory
-Program performs simple memory-to-memory copying. Two blocks of `size` MB are copied to each other `rounds` times. The result is shown in MB/s.
+Program performs simple memory-to-memory copying. Two blocks of `size` MB are copied to each other `rounds` times. The result is shown in MB/s. Remember that this result depends on not only physical memory spead but also on processor.

 ## CPU
 Some set of calculations in integer and floating point arithmetics is performed. The set is called "complex operation" (CO) and is performed `cycles` times. The result is shown in CO/s.

Home modified by Vladimir Ryabtsev

Vladimir Ryabtsev — Mon, 01 Dec 2014 16:03:09 -0000

--- v5
+++ v6
@@ -65,7 +65,7 @@
 * calculates and shows seeking speed in seeks/s.

 ### Write to disk
-Utility creates file `fname` (default is PerfTest.123) and writes `fsize` megabytes into it. To get accurate results choose as much size as possible (use common sense). The reason described in the next section:
+Utility creates file `fname` (default is PerfTest.123) and writes `fsize` megabytes into it. To get accurate results choose as much size as possible (use common sense). The reason is described in the next section:

 ### Why do I get unbelieveable results?
 It's due to caching. Files are written into OS memory cache and the program is informed that write operation finished thus it stops watch. Small file can be written in "zero" time. But actually data is not written to disk completely.

Home modified by Vladimir Ryabtsev

Vladimir Ryabtsev — Mon, 01 Dec 2014 16:01:28 -0000

--- v4
+++ v5
@@ -45,23 +45,38 @@
 ## Disk speed

 ### Read from disk
-For read test two modes are introduced: file and drive. You need administrative priviligies for direct drive access. The only sensible reason to use file mode is absence of administrative privilegies.
+For read test two modes are introduced: file and drive. You need administrative priviligies for direct drive access. Drive mode is preferable. The only sensible reason to use file mode is absence of administrative privilegies. The utility acts as follows:

-* PerfTest opens file or device,
-* In drive mode PerfTest reads `fname` MB from random position of drive,
-* In file mode it reads file named `fname` till the end.
+* opens device or file `fname`,
+* In drive mode it reads `fsize` MB from random position of drive,
+* In file mode it reads file named `fname` till the end,
+* calculates and shows read speed in MB/s.

 You may use any large file for this test.
 Don't have a large file? Make write test with `-nodel` option. Remember about caching in operating system (see further)!

 ### Seeking test
+Again, two modes are introduced: file and drive. You need administrative priviligies for direct drive access. Drive mode is highly recommened. Seeking test on file is possible but the results are not very useful unless you have file that takes the whole drive. The utility performs following operations:
+
+* opens device or file `fname`,
+* chooses random position,
+* reads `block_size` kilobytes from this position,
+* repeats until `num_seeks * 1000` random reads is reached,
+* calculates and shows seeking speed in seeks/s.

 ### Write to disk
+Utility creates file `fname` (default is PerfTest.123) and writes `fsize` megabytes into it. To get accurate results choose as much size as possible (use common sense). The reason described in the next section:

-### Why do I see ultra-fast unbelieveable results?
+### Why do I get unbelieveable results?
+It's due to caching. Files are written into OS memory cache and the program is informed that write operation finished thus it stops watch. Small file can be written in "zero" time. But actually data is not written to disk completely.
+Memory cache is not unlimited. We can overfull it to get more accurate results. When cache is full OS has no choice and it dumps data to disk. The larger file you create the more accurate reults you get. Try to make write test with increasing file size – when speed stops to decrease the real device speed is reached.
+File written persists in cache until it extruded by other data. This means that even though file has been completely written to disk read request may get it from cache again. Remember about it when performing combined write and read test in file mode (`-w` and `-r` options). The file that has just been written is read again from cache, at least partially. Also remember about it when you use `-nodel` option to create large file. You should create large enough file to extrude beginning of it from cache.
+In drive mode caching is also performed, but the utility chooses a random position on disk before reading, thus reducing a chance to meet cached area to minimum.

 ## Memory
+Program performs simple memory-to-memory copying. Two blocks of `size` MB are copied to each other `rounds` times. The result is shown in MB/s.

 ## CPU
+Some set of calculations in integer and floating point arithmetics is performed. The set is called "complex operation" (CO) and is performed `cycles` times. The result is shown in CO/s.

 [[download_button]]