Alert: Use of Large Pages for Shared Memory on Windows Platforms

InterSystems has corrected an issue that can cause InterSystems IRIS® and Caché to not take advantage of large pages for shared memory on Windows, even though these products report that large pages are allocated. This can have detrimental effects on system performance.

The issue results from a change in Windows 10 that requires modification of InterSystems IRIS® and Caché. Note that this issue also affects all InterSystems products that are based on InterSystems IRIS® or Caché. The issue occurs on the following versions of Windows:

• Windows 10 (version 1703 and above)
• Windows 11
• Windows Server 2019
• Windows Server 2022

Windows Server 2016 is not impacted.

For reference, the correction for this issue is identified as RJF533. This correction will be included in all future InterSystems IRIS® and Caché distributions. The correction is also available as an Ad hoc distribution for supported product versions.

InterSystems recommends the following to avoid potentially severe system performance degradation:

• For systems using large pages, defer upgrading to an impacted Windows version until implementing the correction.
• For systems already running an impacted Windows version and using large pages, implement the correction prior to any planned increase in system load.

InterSystems generally recommends the use of large pages in order to improve performance. More information is available in the documentation sections Configuring Large Pages on Windows and memlock.

If you have any questions regarding this alert or need an Ad hoc distribution with the correction, please contact the Worldwide Response Center.