Looking to purchase Dell's 30Inch Monitor

[Speedlimits]

Hi. As stated in the title I am in the market for a 30inch dell monitor so that I can 8 table on one screen. I was reading on dell.com the stuff you need to make this work and came across this:

your PC must have a dual-link DVI-D graphics card that supports 2560x1600 resolution.

Now my PC is pretty old. Dell Dimension 4600 (bought in 2003) so my question is. How do I know if I have a dual-link DVI-D graphics card?