I am using the board with 3 gfx's, the pci-e x1 slot can be used just fine, but you need to short pin A1 with B17 ( https://bitcointalk.org/index.php?topic=36061.0 ), I used a cable tie (got loads of them whenever I get hardware with cables), with exposed ends, it's been running just fine for 2-3 weeks now.