Memory allocation in Xvfb

I have following this blog in setting Xvfb in my ubuntu environment:

http://corpocrat.com开发者_运维技巧/2008/08/19/how-to-install-xvfb-x11-server-in-linux-server/

So I did this: Xvfb :1 -screen 0 800x600x24&

My question is does Xvfb only allocate memory during initialization? i.e. just enough for a display of 800x600x24? So as I have more and more programs (different programs or same program multiple times) display to the Xvfb , it does not allocate more memory?

Thank you.

Use the -noreset option to solve memory usage problem:

Xvfb :1 -screen 0 800x600x24 -ac +extension RANDR +render -noreset

No, Xvfb, like all X servers, will allocate memory as needed. The initial allocation of the screen frame buffer should not grow, unless you ask it to increase the screen size from 800x600, but the X server will still need to allocate memory for every client that connects and for various operations the clients do (allocating pixmaps, creating graphics contexts (GCs), loading fonts, etc.).