I'll get straight to the point, I have two Radeon 4870 cards in my possession. Ordinarily I would Xfire them and call it done, but even though my motherboard advertises as Crossfire capable, it actually only has one x16 slot, the other being x4. I'm currently soliciting opinions on how well this scales. I'm aware that the performance of the second card will be less than optimal, but how much less? I'd have to buy a new power supply to Crossfire, so I'd just like to make sure that my money wouldn't be better spent on something like a Solid State drive. I have googled it, but I could mostly just find a bunch of stuff on crossfiring x8-x8, not x16-x4, so if anyone has information they'd like to share, I'd love to hear it.
The system I'm putting it into is using a Biostar A880 with an Athlon X2, a 500 Watt PS, and 8GB Ripjaws clocked a little over 1600.