Yes, passive, 1.15b.

I'm not taking it too seriously. I don't wanna invest into mining so much money.
1.15b model with Spartan 6 SLX75 is the last model which can be used with free development environment from Xilinx. I wanna play with it and (in some point in a future) don't wanna be stuck with SLX150 FPGA(s), which can't be used for aything else then BC mining.