The NVIDIA RTX 5090 is the objective winner of this comparison, securing victory across the majority of the evaluated specifications. Its most significant advantage is its shader unit count, which is 750% higher than that of the Intel Arc B580. This substantial lead in processing architecture establishes the former as the superior option for raw computational capacity, while the latter maintains a distinct lead in affordability, offering an MSRP that is 88% better than its competitor.

Users prioritizing maximum hardware capability and high-density processing power should select the NVIDIA RTX 5090 for their builds. Conversely, the Intel Arc B580 is the appropriate choice for budget-conscious consumers who require a functional component while benefiting from a significantly lower MSRP. By choosing based on these specific advantages, buyers can align their hardware selection with either the high-performance requirements of the NVIDIA card or the cost-efficiency offered by the Intel alternative.