How can I find my REAL video RAM?

I'm trying to find out how much video memory, and whenever I use the dxdiag method, it shows that I have 1786MB of video memory which I'm pretty damn sure that I don't. The card that I have is an ATI Radeon HD 3600 Series (not what the computer came with; I sent it to best buy for major repairs and it came back with a better video card), and I can't find any speculations online that say how much vRAM it has. The card is overclocked, but only by about 10 MHz. I don't believe that I have 1786 megs of vRAM since I can play games such as World of Warcraft and still get 50-60 FPS on average; much less in combat situations. Any other way to calculate my RAM?|||its been some time since i ran dxdiag but i think its in the display tab. but what you see is true my one is just over 2000meg something like 2043 and it doesnt act like it either it has to run alongside the video card and the RAM if it doesnt it will act quite slow