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Allocation of video memory in systems with integrated graphics units (iGPU)

Introduction

In systems with an integrated graphics unit (iGPU), the main system memory is also used as video memory. The allocation of how much system memory (DRAM) may be used as video memory (VRAM) is handled automatically by the operating system. So, in general, the iGPU can always access as much memory as it needs at any given moment.

In certain use cases, however, it may be useful or even necessary to adjust this allocation manually. This applies in particular to benchmarks, games, or applications that check the available video memory at startup and may refuse to run if the system does not report a certain minimum amount of VRAM right away.

Manual allocation in BIOS setup

Many iGPU models offer an option in BIOS setup to reserve a fixed portion of system memory as video memory. This option is usually labelled “Aperture Size” or “UMA Framebuffer.” Typical values range from 1 GB up to 16 GB. This applies to both Intel and AMD systems.

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If you are using a system with relatively little total RAM - for example 8 GB - and still set 16 GB as video memory in the BIOS, there is no need for concern. In such cases, the system will behave as if the setting had been left on "Auto". There is therefore no risk of making the system unbootable through invalid choice.

Values above 16 GB are generally not provided for in the original vendor code of these BIOS options and we are unable to extend them beyond those given limits.

Manual allocation in the AMD driver control panel

Current AMD Ryzen systems also provide an option for video memory allocation in the AMD "Adrenalin Edition" software.

  • AMD Software → Performance → Tuning → Variable Graphics Memory

Unlike the BIOS setting, the values available here scale with the amount of installed system memory. On a system equipped with 32 GB of RAM, for example, the menu allows allocating up to 24 GB of VRAM.

amd-igpu-vram-allocation-via-driver_screenshot_example.png

Additional screenshots are available here as an animated GIF: amd-igpu-vram-allocation-via-driver_screenshots_animated.gif

For this feature to work correctly, the BIOS setting should remain at “Auto” (default). The actual VRAM value can then be configured directly in the AMD software.