Render window question

[Steve-C]

hi,
question.

Ventuz has render window. Statistics has green bar=gpu.
what is relation of green bar to gpu memory?

Sometime, I use many 3d object. Gpu memory small but ventuz render window green bar 500%~600%. Ventuz slow.
If runtime, this is big problem?

In ventuz, delay or duration like mover slow too. This because gpu?
How I can green bar make short? What do I be careful?

If 500%~600% green bar 10 minutes, ventuz show down?

thank you
Steve