A report created by research company Jon Peddie has shown that AMD has been making decent inroads into Nvidia's overall dominance of the discrete graphics card market. Figures for the fourth quarter of 2017 show AMD with a market share of 33.7% while Nvidia has 66.3%. This is a considerable market share leap for AMD, who managed 27.2% of the market share in 3Q17.
https://www.notebookcheck.net/AMD-makes-significant-gain-on-Nvidia-market-dominance.286838.0.html