Application performance issue


I have created a small application upon VisAD to display cloud retrieval

On Windows 2000, the response ( or display update) to domain range or
display variable range change or color table is much faster than one on
the SGI.  The file IO is also very slow on my SGI (195 MHZ IP30
Processor or CPU: MIPS R10000 Processor).
(My input data file is about 19MB with 20  2D variables,  each variable
jhas 700 by 350 pixels ).

But on Windows 2000, I always run into the problem " out of video
memory" when I have  several display window open at sametime or resize
the display window.  (I have 16MB video memory on my PC).

Anyone has any idea on my problem? and how can I  solve the performance
issue on SGI?

Thanks a lot