Render Statistics
The 
Render Statistics are available from the Visualization menu.
This option displays data related to rendering delays, the number of surfaces, summits and triangles processed, and the GPU memory used.
The consumption of GPU memory is displayed as a gauge for the following elements:
The images and videos used as textures and rendered in the active viewport,
The meshes rendered in the active viewport,
The textures used to calculate relief (bumpmaps) that are rendered in the active viewport,
The lighting environments rendered in the active viewport,
The lightmaps calculated in Shaper and used during the rendering in the active viewport,
Other: other sources of GPU memory consumption, including database resources that are not used in the active viewport, other open software, and the memory reserved by the graphics card's driver,
Free: unused GPU memory.