Although the GeForce GTX 780 shares large parts of its DNA with GeForce GTX Titan, the newer card’s driver does not offer the same option to speed up double-precision performance (at the cost of frequency). Consider this a matter of market segmentation by Nvidia, preventing the 780 from becoming a super-cheap development board for compute apps.
Financial Analysis Performance (FP64)
The Monte Carlo pricing test leaves no doubt that Nvidia purposely (and artificially) dumbs down the GeForce GTX 780’s FP64 capabilities in order to give Titan some breathing space.
With double-precision activated, the 780 retains its lead over the 680, but drops behind the aging GeForce GTX 580 in the Folding@Home benchmark.
Anyone who hoped that the GeForce GTX 780 would be a cheaper option for scientific computing is going to be disappointed. While this is an understandable move, it also wasn't necessary.