---
title: "Server Configuration: max degree of parallelism"
description: Learn about the max degree of parallelism (MAXDOP) option. See how to use it to limit the number of processors that SQL Server uses in parallel plan execution.
author: WilliamDAssafMSFT
ms.author: wiassaf
ms.reviewer: derekw, randolphwest
ms.date: 08/26/2025
ms.service: sql
ms.subservice: configuration
ms.topic: how-to
helpviewer_keywords:
  - "parallel queries [SQL Server]"
  - "processors [SQL Server], parallel queries"
  - "number of processors for parallel queries"
  - "max degree of parallelism option"
  - "MaxDop"
---

# Server configuration: max degree of parallelism

[!INCLUDE [SQL Server](../../includes/applies-to-version/sqlserver.md)]

This article describes how to configure the `max degree of parallelism` (`MAXDOP`) server configuration option in SQL Server by using [!INCLUDE [ssManStudioFull](../../includes/ssmanstudiofull-md.md)] or [!INCLUDE [tsql](../../includes/tsql-md.md)]. When an instance of [!INCLUDE [ssNoVersion](../../includes/ssnoversion-md.md)] runs on a computer that has more than one microprocessor or CPU, the [!INCLUDE [ssDE-md](../../includes/ssde-md.md)] detects whether parallelism can be used. The degree of parallelism sets the number of processors employed to run a single statement, for each parallel plan execution. You can use the `max degree of parallelism` option to limit the number of processors to use in parallel plan execution. For more detail on the limit set by `max degree of parallelism`, see the [Considerations](#considerations) section in this page. [!INCLUDE [ssNoVersion](../../includes/ssnoversion-md.md)] considers parallel execution plans for queries, index data definition language (DDL) operations, parallel inserts, online alter column, parallel stats collection, and static and keyset-driven cursor population.

[!INCLUDE [sssql19-md](../../includes/sssql19-md.md)] introduced automatic recommendations for setting the `max degree of parallelism` server configuration option based on the number of processors available during the installation process. The setup user interface allows you to either accept the recommended settings or enter your own value. For more information, see [Database Engine Configuration - MaxDOP page](../../sql-server/install/instance-configuration.md#maxdop).

In Azure SQL Database, SQL database in Fabric, and Azure SQL Managed Instance, the default `MAXDOP` setting for each **new** single database, elastic pool database, and managed instance is `8`. In Azure SQL Database and SQL database in Fabric, the `MAXDOP` database-scoped configuration is set to `8`. In Azure SQL Managed Instance, the `max degree of parallelism` server configuration option is set to `8`.

For more on `MAXDOP` in [!INCLUDE [ssazure-sqldb](../../includes/ssazure-sqldb.md)] or SQL database in Fabric, see [Configure the max degree of parallelism (MAXDOP) in Azure SQL Database and SQL database in Fabric](/azure/azure-sql/database/configure-max-degree-of-parallelism).

## Considerations

This option is an advanced option, and should be changed only by an experienced database professional.

If the affinity mask option isn't set to the default, it might restrict the number of processors available to [!INCLUDE [ssNoVersion](../../includes/ssnoversion-md.md)] on symmetric multiprocessing (SMP) systems.

Setting `max degree of parallelism` to `0` allows [!INCLUDE [ssNoVersion](../../includes/ssnoversion-md.md)] to use all the available processors up to 64 processors. However, this isn't the recommended value for most cases. For more information on the recommended values for max degree of parallelism, see the [Recommendations](#recommendations) section in this page.

To suppress parallel plan generation, set `max degree of parallelism` to `1`. Set the value to a number from 1 to 32,767 to specify the maximum number of processor cores that can be used during a single query execution. If a value greater than the number of available processors is specified, the actual number of available processors is used. If the computer has only one processor, the `max degree of parallelism` value is ignored.

The max degree of parallelism limit is set per [task](../../relational-databases/system-dynamic-management-views/sys-dm-os-tasks-transact-sql.md). It isn't a per [request](../../relational-databases/system-dynamic-management-views/sys-dm-exec-requests-transact-sql.md) or per query limit. This means that during a parallel query execution, a single request can spawn multiple tasks up to the `MAXDOP` limit, and each task uses one worker and one scheduler. For more information, see the *Scheduling parallel tasks* section in the [Thread and task architecture guide](../../relational-databases/thread-and-task-architecture-guide.md).

You can override the max degree of parallelism server configuration value:

- At the query level, using the `MAXDOP` [query hint](../../t-sql/queries/hints-transact-sql-query.md) or [Query Store hints](../../relational-databases/performance/query-store-hints.md).
- At the database level, using the `MAXDOP` [database scoped configuration](../../t-sql/statements/alter-database-scoped-configuration-transact-sql.md).
- At the workload level, using the `MAX_DOP` option of a [resource governor workload group](../../t-sql/statements/create-workload-group-transact-sql.md).

Index operations that create or rebuild an index, or that drop a clustered index, can be resource intensive. You can override the max degree of parallelism value for index operations by specifying the `MAXDOP` index option in the index statement. The `MAXDOP` value is applied to the statement at execution time and isn't stored in the index metadata. For more information, see [Configure Parallel Index Operations](../../relational-databases/indexes/configure-parallel-index-operations.md).

In addition to queries and index operations, this option also controls the parallelism of `DBCC CHECKTABLE`, `DBCC CHECKDB`, and `DBCC CHECKFILEGROUP`. You can disable parallel execution plans for these statements by using trace flag 2528. For more information, see [trace flag 2528](../../t-sql/database-console-commands/dbcc-traceon-trace-flags-transact-sql.md#tf2528).

[!INCLUDE [sssql22-md](../../includes/sssql22-md.md)] introduced Degree of Parallelism (DOP) Feedback, a new feature to improve query performance by identifying parallelism inefficiencies for repeating queries, based on elapsed time and waits. DOP feedback is part of the [intelligent query processing](../../relational-databases/performance/intelligent-query-processing.md) family of features, and addresses suboptimal usage of parallelism for repeating queries. For information about DOP feedback, visit [Degree of parallelism (DOP) feedback](../../relational-databases/performance/intelligent-query-processing-degree-parallelism-feedback.md).

<a id="Guidelines"></a>

## Recommendations

In [!INCLUDE [sssql16-md](../../includes/sssql16-md.md)] and later versions, during service startup if the [!INCLUDE [ssDE-md](../../includes/ssde-md.md)] detects more than eight physical cores per NUMA node or socket at startup, soft-NUMA nodes are created automatically by default. The [!INCLUDE [ssDE-md](../../includes/ssde-md.md)] places logical processors from the same physical core into different soft-NUMA nodes. The recommendations in the following table are aimed at keeping all the worker threads of a parallel query within the same soft-NUMA node. This improves the performance of the queries and distribution of worker threads across the NUMA nodes for the workload. For more information, see [Soft-NUMA (SQL Server)](soft-numa-sql-server.md).

In [!INCLUDE [sssql16-md](../../includes/sssql16-md.md)] and later versions, use the following guidelines when you configure the `max degree of parallelism` server configuration value:

| Server configuration | Number of processors | Guidance |
| --- | --- | --- |
| Server with single NUMA node | Less than or equal to eight logical processors | Keep `MAXDOP` at or under the # of logical processors |
| Server with single NUMA node | Greater than eight logical processors | Keep `MAXDOP` at 8 |
| Server with multiple NUMA nodes | Less than or equal to 16 logical processors per NUMA node | Keep `MAXDOP` at or under the # of logical processors per NUMA node |
| Server with multiple NUMA nodes | Greater than 16 logical processors per NUMA node | Keep `MAXDOP` at half the number of logical processors per NUMA node with a MAX value of 16 |

NUMA node in the previous table refers to soft-NUMA nodes automatically created by [!INCLUDE [sssql16-md](../../includes/sssql16-md.md)] and higher versions, or hardware-based NUMA nodes if soft-NUMA is disabled.

Use these same guidelines when you set the max degree of parallelism option for Resource Governor workload groups. For more information, see [CREATE WORKLOAD GROUP](../../t-sql/statements/create-workload-group-transact-sql.md).

#### SQL Server 2014 and earlier versions

From [!INCLUDE [sql2008-md](../../includes/sql2008-md.md)] through [!INCLUDE [ssSQL14](../../includes/sssql14-md.md)], use the following guidelines when you configure the `max degree of parallelism` server configuration value:

| Server configuration | Number of processors | Guidance |
| --- | --- | --- |
| Server with single NUMA node | Less than or equal to eight logical processors | Keep `MAXDOP` at or under the # of logical processors |
| Server with single NUMA node | Greater than eight logical processors | Keep `MAXDOP` at 8 |
| Server with multiple NUMA nodes | Less than or equal to eight logical processors per NUMA node | Keep `MAXDOP` at or under the # of logical processors per NUMA node |
| Server with multiple NUMA nodes | Greater than eight logical processors per NUMA node | Keep `MAXDOP` at 8 |

## Permissions

Execute permissions on `sp_configure` with no parameters or with only the first parameter are granted to all users by default. To execute `sp_configure` with both parameters to change a configuration option or to run the `RECONFIGURE` statement, a user must be granted the `ALTER SETTINGS` server-level permission. The `ALTER SETTINGS` permission is implicitly held by the **sysadmin** and **serveradmin** fixed server roles.

<a id="SSMSProcedure"></a>

## Use SQL Server Management Studio

These options change the `MAXDOP` for the instance.

1. In **Object Explorer**, right-click the desired instance and select **Properties**.

1. Select the **Advanced** node.

1. In the **Max Degree of Parallelism** box, select the maximum number of processors to use in parallel plan execution.

<a id="TsqlProcedure"></a>

## Use Transact-SQL

[!INCLUDE [connect-instance-client](../../includes/connect-instance-client.md)]

Copy and paste the following example into a query window and select **Execute**. This example shows how to use [sp_configure](../../relational-databases/system-stored-procedures/sp-configure-transact-sql.md) to configure the `max degree of parallelism` option to `16`.

```sql
USE master;
GO

EXECUTE sp_configure 'show advanced options', 1;
GO

RECONFIGURE WITH OVERRIDE;
GO

EXECUTE sp_configure 'max degree of parallelism', 16;
GO

RECONFIGURE WITH OVERRIDE;
GO

EXECUTE sp_configure 'show advanced options', 0;
GO

RECONFIGURE;
GO
```

For more information, see [Server configuration options](server-configuration-options-sql-server.md).

<a id="FollowUp"></a>

## Follow up: After you configure the max degree of parallelism option

The setting takes effect immediately without restarting the server.

## Related content

- [Intelligent query processing in SQL databases](../../relational-databases/performance/intelligent-query-processing.md)
- [Query processing architecture guide](../../relational-databases/query-processing-architecture-guide.md)
- [Set trace flags with DBCC TRACEON (Transact-SQL)](../../t-sql/database-console-commands/dbcc-traceon-trace-flags-transact-sql.md)
- [Query Store hints](../../relational-databases/performance/query-store-hints.md)
- [Query hints (Transact-SQL)](../../t-sql/queries/hints-transact-sql-query.md)
- [USE HINT query hint](../../t-sql/queries/hints-transact-sql-query.md#use_hint)
- [ALTER DATABASE SCOPED CONFIGURATION (Transact-SQL)](../../t-sql/statements/alter-database-scoped-configuration-transact-sql.md)
- [affinity mask Server Configuration Option](affinity-mask-server-configuration-option.md)
- [Server configuration options](server-configuration-options-sql-server.md)
- [Query Processing Architecture Guide](../../relational-databases/query-processing-architecture-guide.md#DOP)
- [Thread and task architecture guide](../../relational-databases/thread-and-task-architecture-guide.md)
- [sp_configure (Transact-SQL)](../../relational-databases/system-stored-procedures/sp-configure-transact-sql.md)
- [Set Index Options](../../relational-databases/indexes/set-index-options.md)
- [Degree of parallelism (DOP) feedback](../../relational-databases/performance/intelligent-query-processing-degree-parallelism-feedback.md)
- [RECONFIGURE (Transact-SQL)](../../t-sql/language-elements/reconfigure-transact-sql.md)
- [Monitor and Tune for Performance](../../relational-databases/performance/monitor-and-tune-for-performance.md)
- [Configure Parallel Index Operations](../../relational-databases/indexes/configure-parallel-index-operations.md)