More performance and flexibility for Azure SQL Managed Instance Business Critical

Azure SQL Managed Instance Business Critical is designed for demanding, business-critical SQL Server workloads that require high performance, low latency, and high availability. We continue to invest in the service tier to deliver more performance while giving customers greater flexibility in how they configure resources for their workloads.

Today, we’re announcing two new improvements, generally available starting September 28, 2026:

• Higher transaction log throughput for Business Critical
• Flexible memory, enabling customers to add memory independently of vCores on Premium-series hardware

Together, these improvements build on our continued investments in Business Critical, helping customers get more performance from their configurations while giving them greater control over the resources their applications need.

Higher transaction log throughput

For write-intensive workloads, transaction log throughput can be an important performance dimension. Applications that generate large volumes of data modifications can reach transaction log throughput limits before reaching other compute or storage limits.

With this update, we are increasing transaction log throughput for Azure SQL Managed Instance Business Critical.

For Standard-series hardware:

• Maximum log throughput increases from 96 to 160 MB/s
• Per-vCore log throughput increases to 4.5 to 16 MB/s per vCore
• Maximum log throughput is achieved with 10 vCores

For Premium-series and memory-optimized Premium-series hardware:

• Per-vCore log throughput increases from 12 to 16 MB/s per vCore
• Maximum log throughput of 192 MB/s is achieved with 12 vCores

The increased throughput can improve the performance of workloads that generate significant transaction log activity, such as high-throughput OLTP applications, bulk data operations, and batch processing.

The higher per-vCore throughput is also important when sizing an instance. Customers no longer need a larger compute configuration simply to reach the maximum transaction log throughput available from the service tier.

With Standard-series hardware, 10 vCores are sufficient to reach the maximum 160 MB/s log throughput. With Premium-series and memory-optimized Premium-series hardware, 12 vCores are sufficient to reach the maximum 192 MB/s.

For workloads where transaction log throughput is the limiting resource, this provides more flexibility to select a compute configuration that better matches the application's actual CPU requirements.

Learn more about Business Critical resource limits.

Flexible memory is now generally available in Business Critical

Database performance isn't only about CPU and storage. Many SQL Server workloads are memory-intensive, and increasing memory has traditionally also meant increasing the number of vCores.

Flexible memory changes that.

Flexible memory allows you to increase the amount of memory allocated to Azure SQL Managed Instance without increasing the number of vCores.

Starting September 28, flexible memory is generally available for Azure SQL Managed Instance Business Critical on Premium-series hardware, for both locally redundant and zone-redundant instances.

This gives you an additional dimension for optimizing your instance configuration. Instead of increasing compute when your workload primarily needs more memory, you can configure a higher memory-to-vCore ratio while keeping the number of vCores unchanged.

Consider an application whose CPU requirements are already met by its current configuration but whose workload would benefit from more memory. Previously, obtaining more memory could mean increasing the vCore count as well. With flexible memory, you can add memory while maintaining the compute configuration that already meets the workload's CPU requirements.

Flexible memory can be used with both new and existing managed instances, giving you the ability to adjust your configuration as workload requirements evolve.

Learn more about flexible memory for Azure SQL Managed Instance.

More performance where you need it

Higher transaction log throughput and flexible memory address two different resource dimensions, but they follow the same principle: giving customers more control over the resources they need for their workloads.

A write-intensive application might require higher transaction log throughput without requiring significantly more CPU. With the new log throughput limits, that workload can achieve higher transaction log throughput at smaller vCore configurations.

A memory-intensive application might have sufficient CPU resources but require a larger memory allocation. Flexible memory allows additional memory to be configured without adding vCores simply to obtain more RAM.

These capabilities provide more options for aligning the configuration of Azure SQL Managed Instance with the performance characteristics of your application.

Continuing to improve Business Critical

These improvements build on a series of investments we have made in Azure SQL Managed Instance Business Critical. Our focus has been consistent: deliver more performance, provide greater flexibility in how instances are configured, and help customers optimize the cost of running demanding SQL Server workloads.

More performance and configuration flexibility

Previous Business Critical improvements increased performance and expanded the configuration options available to customers, providing greater flexibility when choosing the resources needed for demanding workloads.

These improvements included support for Premium-series and memory-optimized Premium-series hardware, expanding the choice of hardware configurations available for Business Critical workloads.

Learn more about the Business Critical improvements.

More storage without adding compute

We also improved the storage-to-vCore ratio for Business Critical, allowing customers to configure significantly more storage without increasing compute simply to meet their storage requirements.

Business Critical supports up to 16 TB of instance storage, providing substantially more freedom to size compute based on workload requirements rather than storage capacity alone.

For workloads that require substantial storage but comparatively fewer CPU resources, the improved storage-to-vCore ratio can reduce the number of vCores required for the same storage footprint, enabling compute cost savings of up to 50% in applicable configurations.

Learn how the improved storage-to-vCore ratio can reduce compute costs.

Better economics for zone-redundant Business Critical

We also expanded Azure Reservations support for zone-redundant Business Critical configurations, providing another way for customers with predictable workloads to optimize their costs.

Azure Reservations provide discounted compute pricing in exchange for a one-year or three-year commitment.

For zone-redundant Business Critical instances, customers can use reservations for both the standard compute charge and the zone-redundancy compute add-on by purchasing the corresponding vCore and vCore ZR reservation types.

Storage and SQL licensing are priced separately, and customers with eligible SQL Server licenses can use Azure Hybrid Benefit to reduce SQL Server licensing costs.

Learn about Azure Reservations for zone-redundant resources.

And we continue those improvements today

Higher transaction log throughput and generally available flexible memory build on this work.

The common theme is giving customers more control over the resources they need for their workloads:

• More storage without having to add compute simply to increase storage capacity
• More memory without having to add compute
• Higher transaction log throughput at smaller vCore configurations
• More options to optimize the cost of zone-redundant deployments

Together, these improvements make it easier to configure Business Critical around the actual requirements of your application, rather than increasing one resource simply to gain more of another.

Get started

Higher transaction log throughput and flexible memory for Azure SQL Managed Instance Business Critical are generally available starting September 28, 2026.

To learn more:

• Review the Azure SQL Managed Instance resource limits
• Learn more about flexible memory for Azure SQL Managed Instance
• Explore previous Business Critical improvements
• Learn how the improved storage-to-vCore ratio can reduce compute costs
• Learn about Azure Reservations for zone-redundant resources

We’re excited to continue improving Azure SQL Managed Instance Business Critical and giving you more performance, flexibility, and control for your most demanding SQL Server workloads.