I'm sure what your asking.
If your asking what the rated speed of your video memory is I don't believe
there is a program to tell you the rated speed. It is usually printed on top of
the chips and maybe on the box for the video card.
If your talking about what speed your memory is running at you can download
coolbits for Nvidia graphic cards.
http://www.softpedia.com/public/scripts/downloadhero/12-1-31/