When you go to the task manager, you can see how much RAM you're using.
Is there any way to find out how much VRAM you are using?
W7 64 bit here. ATI Radeon HD 4890 card
EDIT:
GPU-Z and HWiNFO don't work.
ATI provides a tool too, but it keeps displaying 35MB in use. No matter what programs and games are open.
PerfStudio works, but is to advanced for everyday use, it is for analysing system recources while running a game. Has a built-in debugger and everything.