You do not, nor should you have two separate cards.  Yur SLI configuration puts both cores on the same card, in the same way that a dual core CPU does.

cybes51, SLI  Dual 1024MB NVidia GeForce Gts 240 is a single unit with effectively two cards joined into one common mount. It appears that you have received what you had ordered. Hope that helps a bit.

That is what i thought prior to my first call with dell, when i was told that the GTS 240 wasn't a dual card, should have known better to just come here first and save myself 5 hrs of calling Dell. Tks for the prompt response.