Kbase 20436: NT Performance Drop/System Freeze Using Above Physical RAM
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
12/11/2002 |
|
Status: Unverified
GOAL:
How to tweak memory performance on Windows NT server
FIX:
One way prevent performance problems is by tuning the server to prevent a large amount of memory to be provided to the system cache. Windows NT Server normally runs in a large cache model, where all RAM not currently used by the system or by applications is marked as available for disk caching.
Follow these steps to tune the server to stop providing unused RAM to the system cache:
1) Start Control Panel Network.
2) Select "Server" from the Installed Network Software box.
3) Click on "Configure".
4) If the option "Maximize Throughput for File Sharing" is
currently selected, you might get better performance during
large file copy operations by selecting the "Maximize
Throughput for Network Applications" or "Balance" options.
5) If you elected to make a change in Step 3, restart your
computer so the change can take effect.
The "Maximize Throughput for File Sharing" option permits the system cache to use more available memory than it would otherwise. In this configuration, the available memory can drop to levels that result in heavy swapping activity on the hard disks in order to accommodate requests from user or system applications that may subsequently need to be swapped into memory.
The cache manager periodically gives up memory that it has allocated so that the system never runs out of memory completely due to caching alone. This can happen whenever a file copy operation is complete or when a threshold value is reached.
Performance drops or freezes are more noticeable on computers with lower total physical memory. The problem also appears on computers with large physical memory but using almost or all the physical memory processes. When more total physical memory is available, the minimum available memory threshold is also higher, which can alleviate the problem.
Changing the settings the Server in Control Panel (above steps) changes the LargeSystemCache value in the Registry. The value can be located in:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control
\Session Manager\Memory Management\LargeSystemCache
"LargeSystemCache" specifies, for a nonzero value, that the system favor the system-cache working set rather than the processes working set. If you set LargeSystemCache to 0 (zero), it has the same effect on removing possible performance problems as does following the above steps in the Control Panel.