We built an array of 10 Quad FPGA boards ZTEX USB-FPGA Each board has 4x Four Xilinx Spartan 6 FPGA LX150 (XC6SLX150) FPGA, speed grade 3N
These boards were originally popular for bitcoin mining. ZTEX sold these boards for 999 EUR (plus EU VAT if applicable) in 2012 with the price gradually decreasing to 349 EUR (plus VAT) in 2015, after which point the boards were discontinued.
John The Ripper's bleeding-jumbo code has support for bcrypt, descrypt, md5crypt, sha256crypt and sha512crypto password hashing algorithms utilizing the ZTEX FPGA boards.
For bcrypt, our ~119k c/s at cost 5 in ~27W greatly outperforms latest high-end GPUs per board, per dollar, and per Watt. For descrypt (where we have ~970M c/s in ~34W) and to a lesser extent for sha512crypt & Drupal7 and for sha256crypt, our FPGA results are comparable to current GPUs'. For md5crypt & phpass our FPGA results are much worse than current GPUs'