H.264 DXVA Benchmarks: QuickSync vs UVD 2.2 vs VP4 vs VP5

[CruNcher]

http://www.gokuai.com/f/B05Yj637KS6yyu75

that's definitely not spark,whyever MediaInfo detects it as such seems to be a bug


x264 - core 79 r1360 528c100 - H.264/MPEG-4 AVC codec - Copyleft 2003-2009 - http://www.videolan.org/x264.html - options: cabac=1 ref=1 deblock=1:0:0 analyse=0x3:0x133 me=hex subme=6 psy=1 psy_rd=1.0:0.0 mixed_ref=0 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 chroma_qp_offset=-2 threads=12 nr=0 decimate=1 mbaff=0 constrained_intra=0 bframes=3 b_pyramid=0 b_adapt=1 b_bias=0 direct=3 wpredb=1 wpredp=2 keyint=250 keyint_min=25 scenecut=40 rc_lookahead=40 rc=2pass mbtree=1 bitrate=6900 ratetol=1.0 qcomp=0.60 qpmin=10 qpmax=51 qpstep=4 cplxblur=20.0 qblur=0.5 ip_ratio=1.40 aq=1:1.00

Strange even with the Metadata Stripped it's still detected as Spark

[NikosD]

Metadata and the 32 first video frames of the file are saying this is Sorenson (CodecID = 2).

H.264 is after the 32 first video frames.

The file is buggy.

MediaInfo currently displays information about the first video frames.

Case solved.

[egur]

@NikosD
ffdshow 4322 and LAV 0.47 offer significant performance improvements with regard to QS.
The 2622 driver also raises performance.
Maybe you should update the scores?

[NikosD]

I was going to update the information of benchmarks, but I'll wait for the release of new LAV 0.47 (with faster QS than 0.46 and maybe the new DXVA2 "native" mode)

I want to test every mode on every system possible.
(DXVA2 copy-back, CUDA, QS, DXVA2 "native" etc)

Also I would like to test CoreAVC 3.1, which should be already available.(Both CUDA and DXVA "native")

[egur]

Very well. Nev and I got some progress fine tuning our code so LAV 0.47 (QS 0.28) shows a great improvement (http://docs.google.com/spreadsheet/ccc?key=0Ajo8vvjNtaZ5dC1abjBSeVlmcnZXSjYwampfamk3ZWc#gid=0).
You should update to driver v2622 for better results. Also post your RAM speed. This has a significant impact on results.

[egur]

@NikosD
The ffdshow QS scores are very old and don't represent current performance...
You can use LAV 0.47 for QS benchmarks as well, it's slightly more optimized than ffdshow.

[NikosD]

Updated everything.

Some odd results appeared. :rolleyes:

[CruNcher]

Sorry but i cant agree rating the Quality especially of a DXVA Decoder only based on it's speed is wrong DXVA implementations are different and some ISVs fix Bitstream issues that other doesn't which depending on how they do it adds overhead. For example Microsofts DXVA or Cyberlinks wont ever playback some Bitstreams that are easily done by CoreAVC or Arcsoft (without needing to fallback to Software), especially if you have made streams with older x264 versions which had bugs you are screwed with most DXVA decoder ;)
So this "this is the fastest" is only 1 Side of the Medal but shouldn't be the only factor taken into account, playback stability imho weights more then speed, though if you really want almost 100% stability you have to use a Software Decoder they cope with mostly any bitstream that a DXVA decoder would fail on also direct API implementations by the Vendor do like nvcuvid,intels quicksync or amds ovd (though even they have issues in their underlaying implementations with several bitstreams, but they are most of the times reacting fast to fix them).

[BetaBoy]

CruNcher... Agreed. Also note it looks like we identified a slow down for DXVA which would explain the results here. We are trying to get it added into CoreAVC 3.1.

[NikosD]

Quality of H.264 decoding should be the same for every bugless decoder.

As a matter of fact there is no such thing as "quality" for H.264.

The bugless DXVA implementation of H.264 decoding, should be handled with the same perception as H.264 decoding.

So, decoding speed for DXVA H.264 acceleration is the number one factor.

Of course it's not the only one, because bugs always exist.

[nevcairiel]

Bugs can also exist in the H.264 stream itself, which technically makes those streams invalid (not standards conform), but trying to gracefully skip/recover those is whats important sometimes. Of course, sometimes you're just at the mercy of the GPU driver or the hardware.

[mark0077]

Hi guys, I'm putting together some benchmarks on my own machine today using LAV / ffdshow decoders, and am finding very interesting results.

Although QS is extremely fast, and I'm getting very high decoding rates with it in both LAV and ffdshow, theres still 2 things that I'm confused about.

1) Some particular files show a large difference in performance between QS in LAV and ffdshow, sometimes with ffdshow being much faster, sometimes LAV being slightly faster. Is it worth me posting the details of these and my system to the likes of yourself nev?

2) Although performance of QS is tremendous and I'm amazed by it, especially compared to my gpu decoding, it uses alot more cpu than other software decoders (about 1.5x - 2x) on my core i7 920. I thought decoding speed and cpu usage might have been more closely tied, but instead I see the opposite of what I expected, higher performance from QS using more cpu.

I was hoping to use FPS output from graphedit to decide what the best decoder was for my system for various types of content, but because I'm using avisynth scripts that I have tuned over time to reach about 90% cpu usage max, the increased cpu usage of QS over other decoders pushes the cpu that extra bit higher causing dropped frames... So its improved performance seems to actually have a negative effect in this case. Is increase cpu usage by using QS normal or should it be as low or lower than other sofware decoders?

[nevcairiel]

QS is a GPU decoder, its not a software decoder. I noticed you say i7 920 - that CPU does not contain a GPU thats QuickSync compatible. You must be confusing some things.

For the record, on my i7 2600k, i get around 500-550 FPS at 100% CPU usage in software decoding, and around 400 fps with QuickSync at ~30% CPU usage (testing done with the Twin Peaks sample from this thread).
During normal playback, QuickSync usually hovers at 1-2%, possibly up to 3-4% for 60fps material.

[mark0077]

doh! I feel stupid. I didn't know about it being it being a GPU decoder :S aaah,

I just tried it on my older core i7 920 and get massive performance figures with QS, much higher than other decoders, even the other dxva ones in LAV on some particular files... I don't know how its supposed to behave on my core i7 but its really fast which is attractive. I guess its still confusing as to why it uses more cpu than other decoding options CUVID / DXVA / other pure software decoders. Maybe I'll ask the developer as to how it should behave on older cpus like mine.

[nevcairiel]

The QS decoder shouldn't even be used when there is no GPU support, it would fallback to LAVs software decoder.

[mark0077]

Ah right. When I use the QS decoder in ffdshow at least, I can see IntelQuicksyncDecoder.dll instances in Process Explorer mpc-hc Threads list. I'll try to clarify with the author what the decoder does on cpus like mine where theres no internal gpu. Its definitely being used by ffdshow and giving massive FPS gains. If I get any interesting feedback I'll post it here.

EDIT: Using LAV Video set to QuickSync, shows the quicksync decoder dll in process explorer also FWIW

[fairchild]

Is there anyway someone can upload twinpeaks.1080.wmv to a working filesharing site like mediafire, the rapidfire link is slow as molasses. I tried googling and came up short. I'd like to run some vc-1 1080p tests and can't seem to find any good 10s clips to use.

[nevcairiel]

Is there anyway someone can upload twinpeaks.1080.wmv to a working filesharing site like mediafire, the rapidfire link is slow as molasses. I tried googling and came up short. I'd like to run some vc-1 1080p tests and can't seem to find any good 10s clips to use.

http://files.1f0.de/samples/twinpeaks.1080.wmv

[fairchild]

Sweet thx Nev.

[wanezhiling]

I got such a broken image (http://i.imgur.com/ODlZ3.jpg) with CyberLink DXVA or HAM on my GTS450(295.73whql) while no problem with my 4650m(12.3).

Did anyone reproduce the issue with Samsung clip?:)

[NikosD]

Added WMV3 results for DXVA QuickSync

[vanden]

Hello I have a HD 6850 and after some test my results are close to your original 5750 !

Avatar 60fps (MS DS) :
Renderer: Enhanced Video Renderer (DirectShow)
Decoder: Microsoft DTV-DVD Video Decoder
Decoder Device: ModeH264_VLD_NoFGT
Processor Device: -
Time: 00:38.471
Average FPS: 51,363
Min/Max FPS: 48 / 54
CPU Usage (%): Avg: 02 Min: 00 Max: 03
GPU Usage (%): Avg: 00 Min: 00 Max: 02

Generally UVD launch with gpu 300mhz / memory 1100mhz ...
In 3d I use AMD overdirve (900/1150).

If I modify my bios (with RBE) is there a chance that it works as well as your (6)750 ?

[NikosD]

It's been months since my last attempt to benchmark and test my UVD.

I remember that I had tried the procedure you propose, to manually change the UVD frequency with RBE, with no success.

Unfortunately my latest attempts to put UVD in 3D mode with my (6)750 have all failed, too.
I think the problem is latest Catalysts (12.4) which have probably closed that "door" to UVD overclocking.

I'll do further tests and report back.

[pokazene_maslo]

Hi.
How do I enable 4K h264 DXVA on my ATI HD6970? Whatever I set in MPC-HC or Pot player the DXVA simply doesn't kick in.

Catalyst 12.4, win7 x64

[vanden]

I'll do further tests and report back.

Thanks

Hi.
How do I enable 4K h264 DXVA on my ATI HD6970? Whatever I set in MPC-HC or Pot player the DXVA simply doesn't kick in.

Catalyst 12.4, win7 x64

No 2160p for AMD card ...
It's exaggerate, AMD announce support of 4k (April 2010/Catalyst 10.4) !!
We are in May 2012 !!

[vanden]

I have found a software (iTurbo On HIS site). It's possible to disable 2D clock and always force 3D clock (900/1150 or more).
I have little improvement :
Average FPS: 55,736
Min/Max FPS: 51 / 58

But it's not as significant in that your tests

[pokazene_maslo]

No 2160p for AMD card ...
It's exaggerate, AMD announce support of 4k (April 2010/Catalyst 10.4) !!
We are in May 2012 !!
why is then dxva checker displaying such support (3840x2160)?

[nevcairiel]

why is then dxva checker displaying such support (3840x2160)?

Because no tool is perfect? :p

In theory at least the 7xxx series cards support it, but when you try to decode a 4K image, only half is decoded and the other half is green. :D

[wanezhiling]

4650M UVD2.0 (http://i1131.photobucket.com/albums/m545/wanezhiling/2012-05-15_183345.png)

Dangerous, when it went to 00:00:04, system hung..:p

[vanden]

I have tested catalyst 12.1 with 3D clock forced : same result as catalyst 12.4 ...

[NikosD]

I have tested catalyst 12.1 with 3D clock forced : same result as catalyst 12.4 ...

You have a 6850 card which uses UVD3.
UVD3 is different than UVD2.2 used by my 5750/6750 card, because UVD3 uses dynamic change of frequency.

Which means that even if you change the UVD3 frequency manually, ATI can put UVD3 back to its default frequency, even if you see the GPU going to 3D clocks.
Internally UVD3 will work to a different (default) frequency.
They can control frequency completely.

Moreover, even in UVD2.2 which doesn't have dynamic frequency, in the original BIOS of 5750 when I put manually UVD2.2 in 3D clocks, I couldn't really put UVD2.2 in 3D mode.
I only saw GPU going to 3D clocks, but UVD2.2 worked internally in default clocks.

It was only after changing my BIOS from 5750 to 6750, that I saw - without altering any setting of BIOS - that UVD2.2 was going to 3D clocks by itself, automatically.
Drivers must had gone crazy with that hybrid card and allowed UVD2.2 to work in 3D clocks, statically.
If UVD2.2 was going to 3D mode, the whole card was remaining to that frequency, until restart.

Unfortunately that is no longer available.

I talked too much here :) and to ATI engineers about the subject and they managed to close that "hole".

With Catalysts 12.4 - I don't know with earlier versions between 12.1 and 12.3, I haven't tried them - it's impossible to put UVD2.2 to 3D clocks.
They have simply closed that "hole" :mad:

The only thing remaining is to try to change 6750 BIOS manually and put UVD2.2 in 3D clocks, but latest version of RBE can't recognise 6750 BIOS completely and I don't have the time or mood to do that.

If I do it, I will report here.

UPDATE 14/06

It seems that DXVA Checker 2.8.2 can put UVD2.2 of my fake (6)750 to 3D clocks and the benchmarks show that it can put it in real!
So we are back again with UVD2.2 working in real 710/1160 MHz!

[pokazene_maslo]

Because no tool is perfect? :p

In theory at least the 7xxx series cards support it, but when you try to decode a 4K image, only half is decoded and the other half is green. :D
Maybe it requires stream with 2 slices? Have you tested 4K with multiple slices? On my HD6970 8 slices doesn't help.

[wanezhiling]

http://i.imgur.com/vvvT0.jpg

http://xhmikosr.1f0.de/samples/2160p/DucksTakeOff/DucksTakeOff_2160p50.x264.CRF24.mkv

I5 3450
HD2500(650-1100)

PotPlayer, evr cp

VP5 has only 30fps.

[NikosD]

Very impressive QuickSync performance for Ivy.
Even HD2500 can put Core i5 3450 to a very low 8% at 2GHz - lowest frequency I think for Core i5 3450 which has a base frequency of 3.1GHz and 3.5GHz max.

But GPU clock is at max 1100MHz and GPU Load is 88%.
I don't know if GPU load is actually VPU load for this clip but it seems that HD2500 goes to the limit to play this clip.

You could check for sure the VPU load with GPA tool from Intel.

I think that a good benchmark comparison with DXVA Checker between HD2500 and HD4000 would be useful to see the maximum performance and the potential of the cards regarding 4K H.264 clips and the differences between them.

[NikosD]

Just tried Win 8 Pro x64 with built-in drivers for ATI 5750.

Unfortunately latest Catalysts for Win 8 (release preview) didn't install - so I don't have CCC, OpenGL , OpenCL etc.

But DXVA acceleration works good with built-in Win 8 drivers and DXVA Checker v2.9.1 has exactly the same decoders.

The performance is more or less the same as with Win 7 and WMP12 and PotPlayer work the same.

I'm writing this post with IE10 (not metro version)

UPDATE:

I managed to install Win 8 release preview drivers, which are older than Microsoft drivers.
I have now OpenGL, OpenCL, CCC etc.

It's interesting that WMP12 and Video application of Metro UI with both drivers (Catalyst, Microsoft) try to play 4K H.264 clips in DXVA mode, not in software (there is no software fallback).
I get a black screen, but the sound is OK.

I'm still waiting ATI to allow 4K playback with future drivers.

[NikosD]

More info about Win 8

Win 7 vs Win 8

Win 8 boots faster, has faster shutdown, less footprint (both in memory and disk) and it's faster overall.

IE10 is very fast

It's a modern, more secure OS but has Metro too :confused:

Start button and gadgets ( I use Network/ CPU/ GPU gadgets all the time) are the big losses - for me.

All applications work good so far - and Win 7 drivers too.

About Win 8 DXVA

First of all, with WDDM v1.2 all hardware acceleration - 2D, 3D, video (DXVA) - goes below the same API D3D11.1

So DXVA no longer uses D3D9 for Video Acceleration, it uses D3D11 like 2D and 3D acceleration.

AMD Catalysts didn't provide AMD MFT codecs (none), because Microsoft did it.

It seems that Microsoft - at last - has put VLD mode for VC-1/WMV3 in MFT codec and added a strange Media subtype to its MS MFT H.264 codec, named:

MediaType_Video 3f40f4f0-5622-4ff8-b6d8-a17a584bee5e

which probably is used for Mpeg4 ASP video format (DivX/ Xvid)

So, with an MFT player - like WMP12 or Video (new player of Metro) you can have HW acceleration for everything (MPEG-2, MPEG-4 ASP, H.264, VC-1/WMV3) with Microsoft's codecs -even with built-in drivers.

I did some preliminary benchmarking and it seems that MS DS/MFT codecs have the same performance as LAV 0.51.3 regarding DXVA.

In pure CPU mode, both codecs DS/ MFT H.264 have the same performance as Win 7 (no optimizations) which is far below LAV Video 0.51.3.

I tested again 4K H.264 clips and they are decoded in HW with both WMP12 and Video applications (no software fallback) and both drivers (Microsoft, Catalyst).

The result is a black screen with audio.

Catalyst drivers gave a small boost in Windows Index for 2D and 3D - from 6.9 to 7.2 - compared to newer built-in drivers.

[NikosD]

AFAIK the 2 most "difficult clips" of H.264 4K resolution are:

1) The 3840 x 2160 version of "Ducks Take Off" at 50 fps and 370Mbps bitrate posted above and

2) The 3840 x 2160 version of "Girls Generation Oh 4in1" at 120fps and 100Mbps at L5.1 ReF 16

I haven't found L5.2 yet.

[nevcairiel]

For the record, the fps of the file doesn't really matter for benchmarking.
100Mbps at 120fps is 0.83Mb per frame, while 370Mbps at 50fps is 7.4Mbps per frame. Clearly, the second is much more complicated to decode.

If you want the most complicated clip, get one with a high bitrate per frame. The FPS does not matter for benchmarking (it only matters for playback).

[NikosD]

I disagree with you because my experience with both benchmarking and playback on various VPU hardware says that high FPS does matter.

There are HW units and SW implementations that have problems in both benchmarking and playback with high FPS but without problems at all with high bandwidths.

For example my normal UVD2.2 can play in realtime and benchmark faster than VP4 various H.264 1080p clips with huge bandwidths >100Mbps that VP4 can't, but at the same time VP4 is faster playing lower bandwidth H.264 1080p clips with high FPS like 60 fps.

Normal - default clocked - UVD2.2 can not touch 60fps with H.264 1080p60 fps no matter what the bandwidth is - low or high.

The example of low performance of SW implementation with high FPS is QuickSync decoder - I think not because of Eric's excellent job but because of Intel's MSDK and driver implementation and HW restrictions of memory operations.

As you know if you try to benchmark or play a H.264 1080p60FPS clip - low or high bandwidth, it doesn't matter - on QuickSync hardware using vanilla DXVA, the results will be excellent.

Very low CPU utilization, very low Power and more than enough FPS.

The very same clip at 60fps with QuickSync decoder (FFDShow or LAV implementation) will give much more CPU utilization, high Power and much lower fps.

So, as a conclusion, "difficult" clips for playback and benchmarking with current HW and SW implementations are those that have high bandwidth, high FPS or both.

[nevcairiel]

The speed of the decoder itself is only influenced by the normalized bandwidth. But higher fps usually has lower (normalized) bandwidth, so in that sense it has an indirect influence - but it all comes back to bandwidth. Sadly bandwidth is usually expressed in a "per second" value, which includes the fps, instead of a normalized/averaged "per frame" value.

When it come to playback, you will see differences though.
Like you said, a high-fps and low-bandwidth clip has higher CPU usage in some implementations. Yes, thats to be expected, because more frames are copied per second from the GPU (like with QuickSync or DXVA2-CB)

But during benchmarking, you just get as many frames as the decoder can output, independent of the fps.

[NikosD]

Interesting reply.

But according to your scheme how could you explain the UVD2.2 vs VP4 situation ?

If you see the benchmarks or if you try to play at normal speed (x1) a H.264 1080p30 fps clip with huge bandwidth ~100Mbps, you will see that VP4 is slower than UVD2.2.

That means - according to your scheme - that UVD2.2 decoder is generally faster than VP4, because it can handle larger normalized bandwidth than VP4.

But that is not true.

Because if you benchmark or play H.264 1080p60 fps clip, independantly of bandwidth, you will see that VP4 is faster than UVD2.2.

Could you explain it according to your scheme ?

[vivan]

That means - according to your scheme - that UVD2.2 decoder is generally faster than VP4, because it can handle larger normalized bandwidth than VP4.No. I think he wasn't comparing different decoders.

Simple example: you can change video fps while remuxing - e.g. increase it by 2 times. Would it change benchmark result? No. However such video will have 2 times higher bitrate.
So when you're using for benchmarking 2 videos and getting some numbers, bitrate doesn't mean anything (since you can get any bitrate by just changing speed of the video).

However when playing video in real time - both bitrate and fps matters.

[NikosD]

I get your point, as I got it from nevcariel.

But still, how can you both explain benchmark results of different decoders like VP4 and UVD2.2 like the ones I mentioned before ?

Why UVD2.2 can output more decoded frames from VP4 at H.264 1080p huge bitrate-low fps clips, but lags at high fps-low bitrate H.264 1080p clips ?

Moreover, the real purpose of video benchmarking is to expose and see the potential of an existing decoder implementation of HW and SW during playback.

So for example if the speed of video decoding during benchmarking for a 1080p30 fps file is 65 fps, then it means that the implementation can almost sure play both 2 such files at the same time (with proper driver and player support) or it can play that file at 2x speed.

On the other hand, if during benchmarking a file that is encoded at 60 fps, gets 40fps then you can be sure that normal playback will be slower than realtime playback.

In my opinion, if you want to check the potential of an existing video decoder (SW & HW) and get the whole picture of its own and compared to the others , you have to check it with difficult clips, so you have to check both parameters - bandwidth and fps.

That's why I proposed two clips.

One with huge bandwidth and high fps and the other one with extreme high fps.

[NikosD]

A lot of new DS filters for Catalyst 13.1 - AMD MJPEG decoder, ATI Ticker, ATI Video Rotation filter, ATI Video Scaler filter.
I haven't seen them before.

Also, officially AMD pulls back 4K DXVA acceleration - only 1920x1080 for Catalyst 13.1

[huhn]

intel 3770k @4 ghz turbo hd4000 stock clock

lavfilter 55.3:

1
dxvan 733 qs 266

2
dxvan 508 qs 163

3
dxvan 797 qs 284

4
dxvan 729 qs 276

5
dxvan 687 qs 269

6
dxvan 649 qs 265

7
dxvan 288 qs 234

8
dxvan 280 qs 213

9
dxvan 311 qs 226

10
dxvan 253 qs 207

4k
crowedrun2160p50 crf24
dxvan 165 qs-

duckstakeoff2160p50 crf24
dxvan 118 qs-

intotree2160p50 crf24
dxvan 146 qs-

oldtowncross2160p50 crf24
dxvan 137 qs-

parkjoy2160p50 crf24
dxvan 159 qs-

and for the lols
amiga long play dune 241 kbit crf 30 640x400p25

dxvan 3088 qs 2081 cpu 1902 30 % cpu

like i said in the quicksync thread i can't use quicksync for 4k sry about that.

in my eyes intel dxva is so damn fast that it doesn't matter anymore...

[NikosD]

Excellent work!

Although we are comparing different versions of LAV (native & QS) between your results and mine, the difference between the two QuickSync generations is huge.

Of course you have overclocked your 3770K, but if you haven't change Base Clock I think the iGPU doesn't change its clock by simply changing the multiplier.

The comparison of QS v1.0 of Core i5 - 2400 (SNB) vs QS v2.0 of Core i7-3770K (IVB) is interesting because they work at almost same clock speed.

Max QS v1.0 clock is 1100MHz and Max QS v2.0 clock is 1150MHz.

Did you see which is the actual clock of your GPU during benchmarking ?

You can check it out with GPU-Z.

In huge bitrate clips the DXVA Native performance is more than doubled, the QS is slightly less.

In smaller bitrate clips, QS performance is close.
Native performance is close to double again.

4K performance is excellent too.

I have some 4K clips with large bitrates and high FPS (60fps & 120fps) but I don't think that QS 2.0 will have a problem in DXVA native mode.

[huhn]

the new ivy bridge driver fixed my 4k problem.

duckstakeoff 2160

dxvan 100 qs 60

with the new driver my duckstakeoff benchmark was a lot slower don't know why.

with quicksync:
the mhz in gpu-z goes up to 850 mhz and then stays at 650 mhz so there is a lot of room left. and the gpu power is at max 1.8 watt

the gpu load from gpu-z shows at max 30%

with dxva:

the igpu goes up to 1150 and uses alot more power then quicksync 6.6 watt

if i can trust gpu-z then quicksync is not that fast but it needs "lot" less power.

[NikosD]

Well, it is known that QS software has its limitations regarding performance, especially for low bitrate clips or high fps clips.
The most obvious bottleneck is copy- back procedure of rendered frames between CPU and GPU.

That's why you see low clocks, because of memory performance bottleneck. It doesn't use QuickSync hardware a lot and it's slower.

Also in real playback mode and benchmark mode it uses CPU a lot more than pure DXVA and it consumes more power than native DXVA.
Check the power consumption during playback of the whole chip (CPU, GPU, QS) and you will find out that QS consumes more power.

QS is useful mainly for movie compatibility reasons and the support of VC-1.

New driver seems that doesn't provide good performance results.
So it's not a good fix, if you fix something and break something else :)

Your numbers provided as benchmark results are average. Right ?

The benchmark figures of 4K sample of ducks are different between your posts.
The image of DXVA checker at the other thread of QS software says 83-90 fps on average but your first post here say a lot more with the old drivers and the overclocked CPU.

Which is right and under what benchmark conditions ?

[huhn]

at the moment 100 is normal the frist screen was made on my hd6770 quicksync ist faster on his own intel gpu.

and the monitor was running in ycbcr so no need for the ycbcr - rgb coversation

[NikosD]

I've just realized that the 4K ducks 50fps clip has so large video bitrate that you need a really fast Hard Disk to keep up, especially in benchmark mode - where you can "play" it in double speed or more with DXVA native.

So, if your hard disk was busy during benchmarking or fragmented, maybe it was a bottleneck for maximum performance.

It would be really interesting if you could move the sample to an SSD - if you have - and run it again to see the results.