But Workstation parts, atleast Quadro had always not so many Shader Cores, that was also the case with GF100. In Quadro you don't need more Shaders, other things like high geometry throughput is more important. For Tesla more Shaders might help a bit, but you might also be very memory bandwidth limited and if you sell a card with 15 SMX in the professionel space it has to be available good. For Titan at 900$ you just can save the few 15 SM parts you'll get and sell them, while the availability will be pretty bad.