DirectX Diagnostic or DxDiag shows wrong total memory

Updated: 03/13/2021 by Computer Hope

Running the Microsoft DirectX Diagnostic Tool may show the incorrect total memory under the Display tab for a video card, as you can see in the image below. In this example, an NVIDIA GeForce 9800GT with 512 MB of video memory is being reported as 3303 MB approx. total memory.

DxDiag video card information with video memory listed

This measurement is only an approximation of the total memory the video card uses and includes the total video memory and shared system memory in the computer.

How the memory is used is shown in the example below. As you can see, the adapter properties show the dedicated video memory and shared system memory.

Display properties properly showing system memory

Additional information