59.94 FPS Choppy Playback

I'm trying to edit and play back 1920x1080 progressive scan footage at 59.94 FPS in the free version of Resolve. In both the source clip and timeline monitors, the footage plays back choppy.

1080p30 works flawlessly.
1080i60 works flawlessly.
1080p60 is choppy.

I've tried MTS AVCHD, ProRes 422 10 bit, MP4 MOV, and MPEG2 video clips at 1080p60. All are choppy.

I even tried using the Media Management dialog box to transcode the source clip to DNxHD. That plays back choppy as well. If I use Handbrake to reduce the frame rate to 29.97, it plays back fine.

Timeline resolution is 1920x1080.
Timeline frame rate is 59.94 FPS.
Playback frame rate is 59.94 FPS.

Optimized Media Format and Render Cache Format are both set to DNxHR SQ.
Playback -> Use Optimized Media If Available is checked.
I have generated optimized media on both the source clip and the timeline.

I have the Resolve cache and Resolve project on a PCIe M2 SSD. The source clips are on 7200 RPM HDDs on a SATA bus in RAID 1 configuration.

Playback is choppy at 60 FPS regardless of media source, CODEC, and cache location.

One thing that is curious is if I set the playback frame rate to 29.97, the video playback is buttery smooth but at half the speed of course. Now if I hit 'L' one more time to increase playback to 2x speed, the video playback is buttery smooth AND at 59.94 FPS (2x 29.97). Of course, that's not something that is going to work for real work but it's curious that it can playback 2x 29.97 perfectly smooth but can't play 1x 59.94 perfectly smooth.

Here's some info on the Resolve version and my system:

Davinci Resolve Version 16.1.2.026

Operating System: Windows 10 Pro 64-bit (10.0, Build 17134) (17134.rs4_release.180410-1804)
Processor: Intel(R) Core(TM) i7-8700K CPU @ 3.70GHz (12 CPUs), ~3.7GHz
Memory: 32768MB RAM
DirectX Version: DirectX 12

Card name: NVIDIA Quadro P4000
Display Memory: 24440 MB
Dedicated Memory: 8089 MB
Shared Memory: 16351 MB
Current Mode: 3840 x 2160 (32 bit) (60Hz)

Monitor Model: HP Z32
Native Mode: 3840 x 2160(p) (59.997Hz)

The P4000 graphics card has 8GB DDR5.

Has anyone else seen similar issues with playback at 59.94 FPS on Windows?

Is there something I'm missing in a setting somewhere?

If I purchase the full version, will it fix this issue or will this be an issue with the paid version as well?

Thanks,
Glen

Just out of curiosty, could you solve this problem? I'm having the same issue and Im tracking down all the users who are experiencing it to see if they could fix it.

Is your source a smartphone?

Is your source a smartphone?

Hey Uli thanks for the reply. No is not. If you want to follow this topic here, you will find way much more information about it... but for waht I could tell reasearching in the forum, this happen to quite a few users, and so far, noone has been able to tell why.

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