What clips are you seeing the issue on? Is there a link to the clip that I can download and see the issue? Also, I am guessing you are using the 3910 driver, correct?
The question is... does/or will intel HD 4600 graphics have the capability of hardware acceleration of HEVC/h.265 or could there come some software decoder that also works???
I am looking into the issue and will get back to you.
Also, found a good read on CNET on this very subject that you may find interesting.
Has any one been able to play those 4k HEVC/h.265 clips 100% smoothly with intel HD 4600, or intel 5200 graphic???
If Strongene's OpenCL decoder doesn't work for you, you have to forget GPU assisted HW acceleration and concentrate on pure SW solutions for now, till other GPU assisted solutions come up.
The fastest SW decoder right now, is the latest LAV video x64 nightly build version and possibly other FFMpeg based versions, always in x64.
You have to search a little to find that version or wait for MPC-HC x64 to adopt it.
Do you also have intel HD 4600 graphic? are you able to play HEVC/h.265 clips 100% smoothly like the one I linked to in post nr 2 higher up on this page ?
Using latest nightly build of MPC-HC x64 from here MPC-HC Nightly Builds you will see CPU usage of almost any 4K HEVC going down below <40% without using HD4600 iGPU (software only solution), with your system (Core i7-4790K)
But the specific files from that page you suggest, it seems to have encoding/muxing problems, because they obviously have a small judder during playback. (a repeatedly spasmodic movement of picture, after a few seconds of normal playback each time)
Try some other 4K HEVC clips or try to transcode/ remux to different formats those clips, maybe using some filters.
Both decoders (Strongene's OpenCL and LAV Video) have the same problem, so I think is the source not the decoders.
Well, it seems that even after the release of the first DXVA HW decoder, the problem still remains unresolved.
After further investigation, it seems that although PowerDVD 14, FFMpeg based CPU decoders (LAV Video, PotPlayer), Strongene's HEVC decoder and even FFMpeg DXVA HW decoder for Intel and Nvidia FAIL to decode it correctly, the problem might not be in the encoding and the clip itself, but in the decoders.
Because there is one video decoder capable of playing that clip, without stuttering and it's the Nvidia CUVID decoder.
So, it's definitely not a performance issue, but rather a decoder's issue that can be resolved right now, if you have a Kepler or Maxwell Nvidia card, preferably with a lot of 3D performance, because DXVA and CUVID decoders are based on shaders and not fixed-function hardware.
I guess there will be a fix for the decoders mentioned above, unless for some reason, the problem is the encoding in a way technically difficult to be understood right now.
If you fiddle a little with the latests MPC-HC 1.7.7-128-X64 players settings and using the new 188.8.131.5277 INTEL Drivers, I can play the "UHD_Soccer 1_Barcelona_Atletico Madrid" clip at full 3840x2160p resolution without any stutter at all on the Dell 4k monitor
I tried MPC-HC x64 v184.108.40.206 with latest official drivers for Haswell v3960 and still stutters.
Where did you find v3977 drivers ?
I downloaded the installer from that link, but after the decompression of the setup.exe didn't work.
I have a Core i7-4790 and the app said that I don't have the right processor for that installer.
Nevermind I'll wait from Intel to publish it officially (that or a newer)
What are the suitable settings of MPC-HC and what do you mean to not ask you ?
Did you do it by chance ?
I also have Core i7 4790K 4,0GHz Socket 1150 with Intel HD Graphics 4600 and windows 8.1 64bit and it worked for me
I just formated and reinstalled windows 8.1 so I hope I can find the right settings again with MPC-HC !
Edit: see next page for MPC-HC settings