The Tahiti XT (FirePro W9000) should have 1024 GigaFLOPS.
That isn't the card to compare it to if you are doing Double Precision workloads.
Tahiti XT can have 1:2, 1:4, 1:8, 1:16 configurations for DP:SP.
925 MHz(XT1): 1,894.4 GFlops/ 1.89 TFlops
1000 MHz(XT2, Enterprise): 2048 GFlops/ 2.05 TFlops
1175 MHz(XT2, Consumer, Uncrippled): 2,406.4 GFlops/ 2.41 TFlops
GK110 will most likely have a turbo boost that disables the SP units if the workload is purely in need for DP power.
I'm going to assume it will basically operate like the 670/680.
GK110 ~2.0-2.5 Teraflops
Then add that these processors are around ~600-700mm² while the AMD solution 352 mm² with the 450-520 mm² biggy coming next year. Nivida K20/GK110 520-550mm² so not only is Xeon Phi more expensive to make it is on a process made for small processors not big.
ASRock Fatal1ty 990FX Professional
AMD FX-8320 Eight-Core Processor
GeiL Leggera 2*8 GB 1866 MHz
Windows 8 64-bit
EVGA 480 GTX SC
Alienware OptX AW2210