The RTX 5090 outperforms the RTX 5080 by 20-30% in 4K gaming per Tom's Hardware and delivers superior 8K results per AnandTech. The RTX 5080 closes the gap on value with lower TGP and cost per frame according to Notebookcheck. Choose the 5090 only if maximum performance is required; otherwise the 5080 is the smarter buy.