Was this page helpful?
Your feedback about this content is important. Let us know what you think.
Additional feedback?
1500 characters remaining
Export (0) Print
Expand All

ProcessModelSection.MaxWorkerThreads Property

Gets or sets a value indicating the maximum amount of worker threads per CPU in the CLR thread pool.

Namespace:  System.Web.Configuration
Assembly:  System.Web (in System.Web.dll)

[ConfigurationPropertyAttribute("maxWorkerThreads", DefaultValue = )]
[IntegerValidatorAttribute(MinValue = , MaxValue = )]
public int MaxWorkerThreads { get; set; }

Property Value

Type: System.Int32
The maximum number of threads. The default is 20.

The value of MaxWorkerThreads must be equal to or greater than the MinFreeThreads setting in the httpRuntime configuration section.

You can have some control over the CPU utilization by setting the number of worker threads and I/O threads, using the MaxWorkerThreads property and, the MaxIOThreads property, respectively.

The difference between the two types of threads is that the latter are bound to I/O objects, such as a stream or a pipe, and the former are traditional unrestricted threads. For Internet Information Services (IIS) version 6.0 and higher, ASP.NET processes requests on worker threads. This is because ASP.NET is integrated within IIS.

These threads are obtained from the process-wide CLR thread pool belonging to an application.


Usually the default values for the allowed threads are sufficient to keep the CPU utilization high. If for some reason your application is slow, perhaps waiting for external resources, you could try to increase the number of threads to a value less than 100.

The following code example shows how to access the MaxWorkerThreads property.

                // Get the current MaxWorkerThreads property value. 
                int maxWorkerThreads = 

                // Set the MaxWorkerThreads property to 128.
                processModelSection.MaxWorkerThreads = 128;

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0
© 2015 Microsoft