Determining acceptable values for counters

[Reviewers: Please check these values.] In general, deciding whether or not performance is acceptable is a subjective judgment that varies significantly with variations in user environments. The values you establish as the baselines for your organization are the best basis for comparison. Nevertheless, the following table containing threshold values for specific counters can help you determine whether values reported by your computer indicate a problem. If System Monitor consistently reports these values, it is likely that bottlenecks exist on your system and you should take action to tune or upgrade the affected resource.

Resource

Object\Counter

Suggested threshold

Comments

Disk

Physical Disk\% Free Space
Logical Disk\% Free Space

15%

 

Disk

Physical Disk\\% Disk Time
Logical Disk\% Disk Time

90%

 

Disk

Physical Disk\Disk Reads/sec, Physical Disk\Disk Writes/sec

Depends on manufacturer's specifications

Check the specified transfer rate for your disks to verify that this rate doesn't exceed the specifications. In general, Ultra Wide SCSI disks can handle 50 to 70 I/O operations per second.

Disk

Physical Disk\Current Disk Queue Length

Number of spindles plus 2

This is an instantaneous counter; observe its value over several intervals. For an average over time, use Physical Disk\Avg. Disk Queue Length.

Memory

Memory\Available Bytes

Less than 4 MB

Research memory usage and add memory if needed.

Memory

Memory\Pages/sec

20

Research paging activity.

Paging File

Paging File\% Usage

Above 70%

Review this value in conjunction with Available Bytes and Pages/sec to understand paging activity on your computer.

Processor

Processor\% Processor Time

85%

Find the process that is using a high percentage of processor time. Upgrade to a faster processor or install an additional processor.

Processor

Processor\Interrupts/sec

Depends on processor; 1000 interrupts per second is a good starting point

A dramatic increase in this counter value without a corresponding increase in system activity indicates a hardware problem. Identify the network adapter causing the interrupts. You might need to install an additional adapter or controller card.You might need to install an additional adapter or controller card.

Server

Server\Bytes Total/sec

 

If the sum of Bytes Total/sec for all servers is roughly equal to the maximum transfer rates of your network, you may need to segment the network.

Server

Server\Work Item Shortages

3

If the value reaches this threshold, consider adding the DWORD entries InitWorkItems (the number of work items allocated to a processor during start up) or MaxWorkItems (the maximum number of receive buffers that a server can allocate) to the registry (under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters). The entry InitWorkItems can range from 1 to 512 while MaxWorkItems can range from 1 to 65535. Start with any value for InitWorkItems and a value of 4096 for MaxWorkItems and keep doubling these values until the Server\Work Item Shortages threshold stays below 3. For information about modifying the registry, see Registry Editor Help

 Caution

•	Incorrectly editing the registry may severely damage your system. Before making changes to the registry, you should back up any valued data on the computer.

Server

Server\Pool Paged Peak

Amount of physical RAM

This value is an indicator of the maximum paging file size and the amount of physical memory.

Server

Server Work Queues\Queue Length

4

If the value reaches this threshold, there may be a processor bottleneck. This is an instantaneous counter; observe its value over several intervals.

Multiple Processors

System\Processor Queue Length

2

This is an instantaneous counter; observe its value over several intervals.

For tuning and upgrade suggestions, see Solving performance problems

 

 

http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/sag_mpmonperf_13a.mspx?mfr=true