Video RAM usage

Is there any way I can see how much video ram is being used? I have a 4GB GPU and my qubes each use 128MB of vram. 4000MB/128MB = 30 I should be able to run about 40 qubes before filling up the vram. My qubes become sluggish after opening 10 or so of them.

Qubes dosn’t use vram of the gpu

Okay, I’ll just keep an eye on my RAM and see if it starts getting slow once I fill it up. I should have bought the crappier, cheaper graphics card.