Very low performance of source clips playback Resolve 16.1.2

This is kind of similar to what was the subject of this topic : viewtopic.php?f=21&t=101786

I switched from version 16.1 to 16.1.2 (free version) and the playback of source clip became super slow.
The author of the mentioned topic was describing playing the timeline with some effects - I have not even tried, as I couldn't reasonably navigate the source files.
The most of the clips in questions are like : GoPro footage, MPEG4 Video (H264) 2704x1520 59.94fps 60006kbps [V: GoPro AVC [eng] (h264 high L5.1, yuv420p, 2704x1520, 60006 kb/s)]

At first it just stuttered when I tried to play it with normal speed. I digged a bit and changed my Nvidia drivers to 'studio' version. It helped a bit, but not much - now I had 100% speed playback just fine, but playing it 2x faster was still stuttering too often. Unusable for browsing a lot of content.

When I downgraded to 16.1.0.055 all went back to normal, comparable to what I had on Davinci 15

It is also worth to mention, that using MPC-HC I can play these clips with 400% speed without any problem, the fans on GPU don't even start to spin.
In Resolve they get going really fast after a few seconds of playback wit 200% speed (this was also the case in Davinci 15)

My system is maybe not excellent but should be really sufficient for such simple task as browsing files.

I have Nvidia GTX 1060 Max-Q with 6GB of memory, 32GB system memory, i7-8750H
It didn't really matter if I played these clips from SSD or normal HDD, behaved just the same.

Also friend of mine complained that after recently switching from version 15 to newest (which happened also to be 16.1.2) the clips (also gopro) became unviewable due to stuttering playback. He switched back to version 15.

Is this problem known?

And bonus question, maybe trivial but not for me: why MPC-HC playback is so much more performant than playback inside Davinci? It is not TIMELINE playback, just source clips playback, so where does the whole CPU/GPU power go?

It is known.
In 16 some licensing changed and the free version is not very capable with H.264/265 clips any more (under Windows, MacOS works fine). Either stay at 15, transcode your clips to a mezzanine codec or get Studio.

It is known.
In 16 some licensing changed and the free version is not very capable with H.264/265 clips any more (under Windows, MacOS works fine). Either stay at 15, transcode your clips to a mezzanine codec or get Studio.

Very weird :O

So is it Blackmagic's policy, or OS vendors policy? You mentioned that on Mac you still have h.264 GPU decoding in FREE version of Resolve 16?

Can anyone point to the exact reason and mention in documentation about this? (I couldn't find it)

And you say that in version 15 , on Windows, GPU decoding is supported for free? Two versions of Resolve cannot coexist, and probably DB cannot be downgraded, so I cannot check it right now during working on some movie..

Also, this is really interesting point, but still doesn't explain massive performance drop between minor releases of (big problems with playback started for me after moving from 16.1.0 to 16.1.2 ), also what experienced author of other topic I linked to in initial post.

Indeed, I have very similar issues with my DJI Osmo Action camera. I've experienced it on both my desktop and laptop machines, which are no $15000 MacPros, but still very fair recent rigs.
I'm also curious why free version of DR 16 has dropped H264/265 support, and would like to read it from official statement by myself, if anyone can point me to.
Thx.

You will not find an official statement, but I'm sure it is some licensing issue. They can't afford to pay to other companies if they give it away for free.

That's interesting, can you elaborate? Pay other companies for what? Is H.264 properitary format? Does it involve some licencing?
Also what is the difference between Mac/Windows in that matter?

MPC-HC player does it for free with great speed..

AVC and AAC are both proprietary codecs that require licensing.

And if you want to know how complex licensing of H.265 aka HEVC can be, read here:
https://nofilmschool.com/three-new-codecs-are-coming

Resolve Studio is a great value at 299!

I'm currently using the studio version of DR 17.4.3 and H.264 High L5.1 was giving me a beast of a time. I am working on a radio edit jumping back and forth cutting all the pauses, ums, etc. for an interview. The slowdowns and stops made it near impossible to continue. I learned that this codec interframe vs intraframe compression: meaning multiple frames data is combined during the compression vs. compression inside a single frame.

So the slowdown makes sense to me, and it surprises me that earlier versions were running smoothly. My solution was to create proxy files using a intraframe compression.