Windows 32-bit Memory Address Space Tuning

4-Gigabyte Tuning (Windows)

4-Gigabyte Tuning

On 32-bit editions of Windows, applications have 4 gigabyte (GB) of virtual address space available. The virtual address space is divided so that 2 GB is available to the application and the other 2 GB is available only to the system.

The 4-gigabyte tuning (4GT) feature, formerly called 4GT RAM Tuning, increases the virtual address space that is available to the application up to 3 GB, and reduces the amount available to the system to between 1 and 2 GB.

For applications that are memory-intensive, such as database management systems (DBMS), the use of a larger virtual address space can provide considerable performance and scalability benefits. However, the file cache, paged pool, and nonpaged pool are smaller, which can adversely affect applications with heavy networking or I/O. Therefore, you might want to test your application under load, and examine the performance counters to determine whether your application benefits from the larger address space.

To enable 4GT, use the BCDEdit /set command to set the increaseuserva boot entry option to a value between 2048 (2 GB) and 3072 (3 GB).

Thanks to Brett for locating this information. It’s useful to know that the system can be tweaked in this fashion.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s