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Text File | 1993-06-18 | 15.8 KB | 345 lines

Program: Cache Test Copyright 1993 All Rights Reserved Version: 5.0 a Author: George Spafford Date: June 18, 1993 PURPOSE: To allow users to objectively test the effectiveness of their disk caching software. Cache Test is an independent product and is not supported by any manufacturer. GROUNDWORK: Cache Test tests drive performance by writing data to a specified, or the default, drive. Sequential tests are performed by writing randomly generated fixed length strings to a DOS Text file. Each record consists of n number of identical characters plus a carriage return (ASCII 13) and line feed (ASCII 10). By default, the program writes 513 byte records. This translates to 511 bytes in the record plus the CR and LF. If we were to imagine 8 character records, and that ^ is a CR and + is a LF then the data looks like this. aaaaaaaa^+ 33333333^+ --------^+ zzzzzzzz^+ The characters that make up the record are randomly generated. The random routine is seeded by the timer tick every time it is called to increase the random selections. Characters range from ASCII 32 to ASCII 252. Random records are written to the disk using a random access file structure. Each record consists of randomly generated bytes and two record separator characters. As with the sequential file structure, the number of characters written to the disk is the specified record size - 2 + 2 record separators. It is very similar to the sequential except that it allows random movement through the file. You can view any off these files by pushing CONTROL-BREAK during their creation and then use your favorite disk editor or file viewer. The "DIR Test" consists of Cache Test reading the root directories of either the specified or default drive and then reading the files in those directories. It will repeat this process until it reaches the required number of reads. The more directories you have in your root the better. To be specific, it reads the tree and then counts the number of files in each directory. The value you see it totaling is the number of files + the number of directories + 1 root directory. However, it will keep incrementing by looping the test until the desired number of reads has taken place. Now, let's say that you run the default 10,000 record (count) test. Let's also say that you have a drive witth 2,500 files and directories - the program will need to loop through the drive 4 times in order to meet its test requirements. If you limit the number of records to 2,500 by using the command switch /N:2500 then it will only need to read the tree once. Usage: CT [switches] MAKE SURE YOU HAVE SPACES BETWEEN THE SWITCHES - IF YOU DO NOT, CT WILL NOT BE ABLE TO INTERPRET THE SWITCHES CORRECTLY. /A Performs all tests [this is the default if just CT is run]. /C Specifies that the /L: log file is to be created and not simply appended to. /D Perform DOS directory services test. /D:d Drive to test. "d" is the drive letter. /L:logto Specifies the file name or device to log to. "logto" is the name. By default, data is appended to this. /C must be specified if you want to create a new file and NOT append. /N:nnnn Specifies how many records to write. "nnnn" is the number. 10,000 is the default. If you are processing a directory test, this is how many directory entry reads that CT will perform. /P:pppp Specifies the number of test passes. "pppp" is the number. 1 is the default. /R Perform random access tests. /S Perform sequential tests. /S:sss Specifies the individual record sizes. "sss" is the record size. The default is 513 bytes. Specify the total size that you want a record to be. THE MAXIMUM VALUE FOR THIS IS 16,384. IF YOU GET A STRING SPACE ERROR, YOU WILL NEED TO MAKE THIS VALUE SMALLER THAN WHAT YOU SET IT AT. A small hint is to set your sizes = to a factor of your sector size + 1 byte. My sectors are 512, as are most peoples, and then add 1 = the 513 byte default record size. /W Pause after each screen. /X Exclude screen writes during the testing phase to remove the video bottlenecks. Use /A to run all tests. /D /R /S specify individual tests. Examples: CT /N:1000 /P:5 /W 1000 record test, 5 passes, wait after each screen completes. CT /N:5000 /S:1025 5000 record test, 1025 byte records. CT /N:5000 /W /R /D 5000 record test, wait after each screen, perform only the random and directory tests. CT /L:PRN Perform the default test one time and log it the printer. THE DISPLAY: Please note that the total time values will not add up to the displayed individual test times. This is because I have used double-precision floating point variables to hold my timer values. While you see only two decimal places on the screen, there are a bunch that you do not see. The total values are the result of the summation of the individual test scores, the totals are not timed results - they are mathematical results subject to errors in rounding. Also, the averages column is calculated by adding the floating point numbers together and then dividing by the current pass number - NOT the total number of passes. STOPPING THE PROGRAM: CONTROL-BREAK will terminate the program execution safely. Note, you will probably leave a file named ##TEST##.CT in the root directory of the drive that you were testing. You will need to delete that by hand OR CT will delete it the next time it is run. HISTORY: v5.0a 06/18/93 The directory test bombed on drives with over 250 directories on them. The program will now process 500 entries before looping. This means that if you have 1000 directories, the program will only actually use 500 of them to perform its tests. Also, the program checked for disk space before it performed the directory tests - this is not necessary and now space is only checked before the sequential and random tests are performed. v5.0 06/08/93 Can you say "Major Revision?" This version was rebuilt from the ground up and shares very little with previous versions. Some of the modifications in this program are a direct result from input by Herb Chong. If it wasn't for Herb's input, the DIR test wouldn't be here and test data wouldn't be randomly generated. Thank you very much Herb. A lot of the command line switches have changed. You may need to invoke CT with the /? to see the new ones. Things that are new: - Changed switches - Changed tests - Changed reporting - Changed compiler - Changed my office! v4.3c 07/09/92 pm Heck ... I can't win for losing. I have spent several hours now debugging the variable overflow problem. I believe that they have all been eliminated now. To say "sorry," you can have VT 1.1 also if you choose to register (or are already registered to) Cache Test - this just applies to people registering 4.3 or who are already registered now. v4.3b 07/09/92 am Ooops, I switched to explicit variable typing and ran into a problem when file sizes exceeded the limit of an integer variable (32,767) and the program bombed. It's all set now. v4.3 07/06/92 All screens can now be logged to a file or device. This logging no longer requires that the pass count (/P:) be greater than 1. Every second data screen (excluding the final summary) has a form feed added to it to prevent printing across paper perforations when logging to a printer. The summary screen now displays the command line that was used. ** Due to the volume of mail that I am receiving, I am forced to stop responding to every piece of mail unless you have questions. I'm really sorry for that one folks, but it is seriously taking time away from me when I could otherwise be coding. V4.2 01/10/92 Using the /L: switch, a user can now specify where he/she would like the summary screen to go (nice idea Jim). Also did a little house cleaning on the program in general. Happy New Year everyone. I would like to thank three people especially for all of their tolerance and helpful suggestions: Tim Aright of Queued Access, Wayne Keeter of Wayne's World, and Jonathan Fisk. V4.1 11/13/91 Well Owen, I thought about it. The screen counters can now be disabled using the /X switch on the command line. Note, there are many variables that affect cache performance. It was never my intention to test cache performance across machines. BUT, it is a good idea to allow the user the ability to decide for his/her self as to whether they want to or not. If you disable the counters, there can be some long pauses - especially for the Random Read/Write test - so be patient. CT now has the extremes - a lot of counters or none at all ;-) V4.0 10/29/91 Whew... This one has quite a few updates: 1. COLOR (makes things a lot easier to read). 2. Tracking of timer ticks has been tightened down. 3. Created the ability to perform a number of tests and then present a summary screen with averages using the /P:ppp switch. 4. /W switch added for pausing after screens. V3.5 9/03/91 In response to Mike Focke's request for counters in the crescendo and butterfly tests, I have again enabled them. And Mike, thanks for the suggestions ;-) V3.1 8/26/91 The timing routine is now based on the presence of 18.2 clock ticks per one second. The 100ths decimal location is still weak, but improved. V3.0 7/10/91 Well, I accessed the BIOS segment for clock ticks to create the decimal level counters. The second decimal place is weak in terms of its accuracy, but I decided to leave it in. For those of you worried about significant digits, the algorithm used for this uses 18 clock ticks to generate one second of time. The test records are now 32 bytes total. Output screen formatting is improved. If the program is invoked without any parameters, it executes on the active drive with a 10,000 record test made up of 32 bytes. All user input now occurs on the command line through the use of switches. V2.6 5/24/91 I honestly did not intend another update so soon. It was pointed out to me that the file structure that I had been using was variable. As such, it made ratio comparisons somewhat difficult. Now, the default fixed record length is 32 bytes (the test record count is still 10,000). The user can specify the record length by using the /F:bbbbb switch. "bbbbb" must be between 0 and 32,765. Since the values are now fixed, a user can do a little math (remember that subject folks??) and discern the records per second and so forth. Do note, that two bytes are added to the test string in the files (CR/LF to be exact) that is why the maximum byte size that a user can specify is 32,765 and not the 32,767 legal default limit. V2.5 5/22/91 1. An actual test file byte size field has been added. This should allow users to track the actual sizes of the test records being written. 2. Some users suggested that truly random reads and writes should be added. This serves to get away from any form of sequentialized data. 3. Again, more cosmetic touchups. V2.0 5/16/91 Due to some users having limited drive space, switches were added to allow for different size tests to occur. I was somewhat hesitant to do this because it negated the ability to call results "standard," but what really is standard? Switches were also added to allow users to select what tests they want to run. For now, all that can be specified is whether or not to run all tests, sequential tests only, or random tests only. The ButterFly test was also added in an attempt to give look-ahead caches a hard time. Some of the caches that use a FIFO method of purging will have a heck of a time with this one. Added timers/cleared up timers for the sequential and overall tests. Also speaking of timers, to avoid slowing down some routines, I have removed some of the video effects that were for the user's benefit only. Special thanks to Jonathan Fisk for all of his suggestions and debugging efforts. Special thanks also go out to Tim Akright, the sysop of Queued Access for all of his support. V1.0 5/10/91 Well, I released it. That pretty well sums it up. I hope this program helps you evaluate some of your problems or even makes some solutions/benefits clear. This program is released as shareware. Its price is $10 for each concurrently used copy. Sincerely, George Spafford 3003 LakeShore Drive, #216 St. Joseph, MI 49085 I can be reached via a modem on EXEC-PC or CHANNEL-ONE BBS. My local BBS is Michigan Online 19200-8-N-1 (616) 429-3414 Sysop: Zeke Torres. Code CopyRight: 1993 - George Spafford All Rights Reserved. CACHE TEST IS DISTRIBUTED AS IS. THE AUTHOR (GEORGE SPAFFORD) MAKES NO WARRANTY OF ANY KIND, EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, WITH RESPECT TO THIS SOFTWARE AND DOCUMENTATION. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DAMAGES, INCLUDING LOST PROFITS, LOST SAVINGS, OR ANY OTHER INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF OR THE INABILITY TO USE THIS PROGRAM.