Very poor frame pacing, not sure how to fix it

[Hotdog]

I just got this on my PC, the frame rate is mostly locked to 60fps based on steam's FPS counter. However while playing, the game stutters and and visually, it feels jittery. It felt to me that the frame times is wildly uneven.

I decided to use FRAPS to capture it and indeed, my suspicions were true. There are several times where it takes takes 33ms for the next frame to refresh, and immediately afterwards a a second frame. So instead of running at a flat smooth 16.66ms refresh rate, it kind of suddenly renders 2 frames back to back at 33.33ms. Essentially the game will randomly drop down to 30 fps for a single frame render before going back to 60 fps.

I can't seem to figure out anything on my system that could be causing this issue (i5 4670K + GTX1070Ti should be sufficient). I have no background tasks running (outside of FRAPS).

EDIT: I'm running at 4K Resolution and 60Hz (although it doesn't let me select 60Hz, it is locked to 59Hz for some reason, but selecting it then re-entering the options menu show 4k resolution at 60Hz). I've tried both with and without VSync, and the results are similar, with the fluctuations being less frequent with VSync on.

[皮特]

Your question is a little strange. I don't think this delay is likely to affect the game experience.

[fizzd]

Hi, sorry for the strange performance, we're also quite puzzled. It doesnt seem like lag. We will double check the vsync setting, its possible it's related to that - and get back to you soon.