ok so I have 2 3870s cause I got a really good deal on the 2nd one, but neither one came with a bridge. So I found this Newegg.com - Crossfire Bridge is that what I need?
That's exactly what you need, but you need one per card.. so you need two.. but all AMD cards give you the bridge when you get the card unless you went OEM, but get two, put them both in your PCI-e Slot, then slap the bridges and connect the cards