Ultra-Setting might possible be a bit to much for a low- or lower-middle -end system , in special >Full-HD 
Try to reduce a bit the vectordata / LOD… in parallel check which component is you bootleneck.
Ultra-Setting might possible be a bit to much for a low- or lower-middle -end system , in special >Full-HD
Try to reduce a bit the vectordata / LOD… in parallel check which component is you bootleneck.