The Intel Arc B580 is the objective winner of this comparison, securing victories in eleven out of thirteen measured categories. Its most significant technical advantage is its FP16 performance, which is 152% higher than that of the NVIDIA GTX 1660 Ti. This substantial lead in computational capability establishes the Intel Arc B580 as the superior hardware choice based on the provided specifications, as it outperforms the NVIDIA GTX 1660 Ti in nearly every metric analyzed.

Users prioritizing raw computational power and modern hardware capabilities should select the Intel Arc B580 for its dominant performance advantages. Conversely, the NVIDIA GTX 1660 Ti remains the appropriate choice for those who specifically require a more power-efficient component, as it holds a 37% advantage in TDP. Choosing between these two depends on whether the user values the significant FP16 performance gains of the Intel card or the lower power consumption offered by the NVIDIA alternative.