I don t think they properly optimized this for the 970 at all.
Doom eternal 970. And those results are assuming a 1920x1080 screen resolution at high setting level. I ve got a 970 and an i7 3820 and while my rig is getting pretty outdated i was able to play doom at 1080p 60 fps with most graphics options maxed. The textures look like and i still get wild frame drops. You should be able to reach 60 fps with your gpu.
Not possible without intel sde. Booting up doom eternal with the 6 year old geforce gtx 970 4gb looks like it will return a reliable 61 fps. My buddy is using same gpu and and same cpu and he has no issues playing doom on 60 fps without any drops.