Original sentence: Additionally, while GPUs are highly efficient at single precision calculations they are not nearly as fast in double precision (DP) operations with the same Nvidia Tesla C1060 capable of 78 GFLOPS in double precision  and the AMD FireStream 9270 capable of 240 GFLOPS in double precision
Edited sentence: However, whereas GPUs are highly efficient at single precision calculations they are not nearly as fast in double precision (DP) operations with the same Nvidia Tesla C1060 capable of 78 GFLOPS in double precision  and the AMD FireStream 9270 capable of 240 GFLOPS in double precision