Lower frame rates with native 4k vs DSR

[Ice3m]

Been doing some research, as I have a 4k tv now, I switched the old DSR to a native 4k resolution. It seems people are saying with DSR there should be no drop in framerates or difference in the resources with DSR vs native 4k. I am finding in games like Battlefield 1, where DSR 4k would run on ultra at 60 FPS but moving to Ultra native 4k drops from that solid 60 to about 42 FPS. Is this something with my machine or should a drop be expected with DSR vs 4k?

System:
Windows 10
16 GB Trident Z 2400 DDR4 Ram
Intel I7-8700k CPU
GTX 1080 GPU

 

[TechyInAZ]

That's really odd, your 100% positive your running actual 4k DSR and not 2k DSR???

 

[Ice3m]

I am currently on Native 4k as I got a 4k tv, but I was getting 60 FPS solid with the 4k DSR, after changing to the Native 4k, I got the FPS drop. There shouldn't be a difference in 4k native vs 4k DSR right? 100 % sure I was on 4k DSR originally.