sentences:  However, SATD can still be optimized considerably with SIMD instructions on most modern CPUs.The benefit of SATD is that it more accurately models the number of bits required to transmit the residual error signal.As such, it is often used in video compressors, either as a way to drive and estimate rate explicitly, such as in the Theora (since 1.1 alpha2) encoder, as an optional metric used in wide motion searches, such as in the Microsoft VC-1 encoder, or as a metric used in sub-pixel refinement, such as in x264.