Determining acceptable values for counters

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