I have done some measurements 

Measurements of bandwidth usage:

This branch here:

    http://cgit.freedesktop.org/~sandmann/xf86-video-qxl/log/?h=trackimages

will produce various types of information in the X log file when the
option "EnableImageStats" is given in xorg.conf. Specifically, it will
track whenever an operation triggers a fallback and record the number
of (uncompressed) bytes in the resulting image upload along with a
reason that the fallback happened.

This repository:

     http://cgit.freedesktop.org/~sandmann/imganalysis/tree/

contains a Python script that will read the resulting X log files and
do some rudimentary analysis on it. There is also a set of log files
generated as follows:

cnn.log:
	- Log in
	- Open Firefox
	- Go to www.cnn.com

pinterest.log:
	- Log in 
	- Open Firefox
	- Go to pinterest.com
	- Scroll down for a good while (the site has inifinte scrolling)

oofice.log:
	- Log in
	- Open OpenOffice writer
	- Open this document:  
	       http://www.freedesktop.org/~sandmann/tutorialOOoBase.odt
	- Scroll to the end

Each type of log file exists with image caching turned on and
off. Caching of *fallback* images was turned on in all cases.

The results, somewhat massaged show that 





generated by going to the web sites www.cnn.com and www.pinterest.com
and scrolling down, and from starting OpenOffice 

	  Repeat these with 64, 256 MB of video memory:

- Log in
- Open firefox
- Go to pinterest.com

- Log in
- Open firefox
- Go to cnn.com

- Log in
- Open firefox
- Go to reddit.com

- Log in
- Open OpenOffice
- Open some document (tutorialOobase)



 according to:

    - 


This tree:

    http://cgit.freedesktop.org/~sandmann/imganalysis/tree/

contains some X log files generated with this branch:

of the QXL driver and a script to analyze those log files.







Using this script:

    http://cgit.freedesktop.org/~sandmann/imganalysis/tree/