You know (and granted I'm no expert) I've always wondered why don't fpga mining board designers just find the cheapest FPGA chip and slap a whole bunch of them on a PCB and cluster them. For example put 8 Cyclone IV chips on one board and get 600 Mh/s 
But the problem may be getting them cheap enough without the need to buy them in massive bulk quantities...to quote a website: "The EP4CE6 and EP4CGX15: Starts at $3 and $6 for 250K pieces"
Anyone got $750,000 lying around?
But the problem may be getting them cheap enough without the need to buy them in massive bulk quantities...to quote a website: "The EP4CE6 and EP4CGX15: Starts at $3 and $6 for 250K pieces"
Anyone got $750,000 lying around?
The cheapest FPGA chip (best MHs/$ ratio) is the Spartan-6 LX-150 at the moment. Forget the EP4CGX15 or even the EP4CE6, first one I've used in another project. As long no one like wonderminder has any magical trick to squeeze much more out of this architecture then currently possible, it desn't make sense. I don't know where you get the EP4CGX15 for only 6$, even in high volumes (normal price ~20$ for about ~100pcs), but if you need higher volumes of the Spartan-6 LX-150 you will also get a much better price then in low volumes.