How can I see the contents and allocations of my video card memory, either in real time or in Pix or any other (free) diag program? How can I poll the available video memory from a program before making allocations? What is the best way to fine tune allocations to video memory? I just realized that allocating beyond the available memory seems to crash the computer with no warning. How do I avoid this while still taking advantage of the full available memory? I'm using XNA at the moment but am porting to Sharp DX.

Thanks

In general there is usually no need for the fine-grain video memory query that you required. The api you are using should provide some facility to report out of memory exceptions. As long as you check for these and act according, you should be able to accomplish your said goal. I know is more reactive than proactive, hope that helps.

AFAIK, nothing you can do in a normal user space process or in/with XNA/DirectX should be able to crash the system

Assuming some sort of ideal driver free from bugs.