Compression Performance Tuning in Systems Management Server

ID: Q121555

The information in this article applies to:

Microsoft Systems Management Server versions 1.0, 1.1, 1.2

SUMMARY

The process of creating a data-compressed package (*.PKG) to be transmitted through a Systems Management Server sender involves intense use of the central processing unit (CPU) for the data-compression algorithm. The frequency at which Systems Management Server will yield the CPU during compression can have a dramatic effect on performance; this article discusses this type of tuning. There are several Registry parameters for this purpose.

MORE INFORMATION

WARNING: Using Registry Editor incorrectly can cause serious, system-wide problems that may require you to reinstall Windows NT to correct them. Microsoft cannot guarantee that any problems resulting from the use of Registry Editor can be solved. Use this tool at your own risk.

During a package compression, a block of data is submitted to the compression algorithm and this call returns a compressed block. A large number of these calls can take a large amount of CPU time, so we have a timer that allows Systems Management Server to yield the processor for the specified amount of time. The default is 75 milliseconds. In addition, you can set a Registry entry under:
```
      HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SMS\Compression\ 

      "Yield Time" (DWORD) [this is in milliseconds of yield time per
      compression block] 
```
If compression appears to be hogging your system, try setting this to 100 or 125. For systems with lots of RAM and CPU power, values of 1-20 might be usable, and this would speed up compression somewhat.

There are 7 levels of compression (1 through 7); a level of 1 (default) providing the least compression and greatest speed, and a level of 7 providing maximum compression and taking additional time. This value is located at:
```
      HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SMS\Compression\ 

      "Compression Level" (DWORD) 
```
In addition to the degree of compression desired, compression can be disabled by setting the value below to "No". The default is "Yes".
```
      HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SMS\Compression\ 

      "Enable Compression" (REG_SZ) 
```
Two-to-three megabytes (M) of memory resource can be saved by disabling compression; however, greater disk space will be required to store the package files because they will not be compressed.

Decompression Buffer size:
```
      HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SMS\Compression\ 

      "Decompression Buffer Size (Log2 Value)" (DWORD) 
```
This value specifies the number of buffers to be used when decompressing a package file. It defaults to 15 and can be set to a value of 1 through 31; however, for Systems Management Server version 1.0, values greater than 15 are ignored.

Additional query words: sms prodsms

Keywords : kbnetwork smshowto smsconfig
Version : winnt:1.0,1.1,1.2
Platform : winnt
Issue type :