HTPC Aspects : HQV 2.0 Benchmarking and Video Post Processing in Action

HTPC enthusiasts are often concerned about the quality of pictures output by the system.  While this is a very subjective metric, we have decided to take as much of an objective approach as possible. Starting with the Core 100 review in 2010, we have been using the HQV 2.0 benchmark for this purpose.

The HQV 2.0 test suite consists of 39 different streams divided into 4 different classes. The playback device is assigned scores for each, depending on how well it plays the stream.  Each test was repeated multiple times to ensure that the correct score was assigned. The scoring details are available in the testing guide on the HQV website.

In the table below, we indicate the maximum score possible for each test, and how much the Zotac GT 640 was able to get. As mentioned in the previous section, we used NVIDIA Graphics Driver v301.42 for the benchmarking.

 
HQV 2.0 Benchmark - Zotac GT 640
Test Class Chapter Tests Max. Score Zotac GT 640
Video Conversion Video Resolution Dial 5 5
Dial with Static Pattern 5 5
Gray Bars 5 5
Violin 5 5
Film Resolution Stadium 2:2 5 5
Stadium 3:2 5 5
Overlay On Film Horizontal Text Scroll 5 5
Vertical Text Scroll 5 3
Cadence Response Time Transition to 3:2 Lock 5 5
Transition to 2:2 Lock 5 5
Multi-Cadence 2:2:2:4 24 FPS DVCam Video 5 5
2:3:3:2 24 FPS DVCam Video 5 5
3:2:3:2:2 24 FPS Vari-Speed 5 5
5:5 12 FPS Animation 5 5
6:4 12 FPS Animation 5 5
8:7 8 FPS Animation 5 5
Color Upsampling Errors Interlace Chroma Problem (ICP) 5 5
Chroma Upsampling Error (CUE) 5 5
Noise and Artifact Reduction Random Noise SailBoat 5 5
Flower 5 5
Sunrise 5 5
Harbour Night 5 5
Compression Artifacts Scrolling Text 5 5
Roller Coaster 5 5
Ferris Wheel 5 5
Bridge Traffic 5 5
Upscaled Compression Artifacts Text Pattern 5 3
Roller Coaster 5 3
Ferris Wheel 5 3
Bridge Traffic 5 3
Image Scaling and Enhancements Scaling and Filtering Luminance Frequency Bands 5 5
Chrominance Frequency Bands 5 5
Vanishing Text 5 5
Resolution Enhancement Brook, Mountain, Flower, Hair, Wood 15 15
Video Conversion Contrast Enhancement Theme Park 5 2
Driftwood 5 2
Beach at Dusk 5 2
White and Black Cats 5 2
Skin Tone Correction Skin Tones 10 0
         
    Total Score 210 178

We find that score closely tracks what we had for the GT 540M in the ASRock Vision 3D 252B review. In fact, the only difference is the fact that the horizontal scroll response time has been improved a bit, enabling it to score two more points in that test. Given that the GT 540M had no trouble deinterlacing 1080i60 content, it was not a surprise to find that the GT 640 sailed through those tests. In the next section, we will look at some rendering benchmarks to see how deinterlacing operations load up the GPU. Chroma upsampling algorithms are passable, and there is no difference in quality between what was obtained through the 540M and what we got with the GT 640.

In our review of the video post processing features of the GT 540M, we had indicated that the contrast enhancement and skin tone correction features didn't work. We found no change in the v301.42 drivers. However, we did find contrast enhancement working with the black level testing clip in the AVS HD 709 calibration suite. This just proves that the dynamic contrast enhancement feature in the NVIDIA drivers doesn't work as effectively as Intel's or AMD's.

Should the low HQV score or lack of proper dynamic contrast enhancement prevent you from choosing the GT 640 for your HTPC? Definitely not! The nice aspect about NVIDIA GPUs is the fact that there are lots of HTPC software packages available to take advantage of the GPU resources. As long as the hardware deinterlacer works (it does, as the HQV scores for those tests indicate), and there are enough shaders and other computing resources available to let madVR work its magic, the HTPC end-user has no reason to worry. Advanced HTPC users tend to distrust any post processing done by the drivers, and would rather not let the driver mess with the video output by applying its custom post processing algorithms (which tend to break with every new driver release).

However, video post processing algorithms are not the only issue-prone HTPC aspects in the driver. Proper black levels are necessary irrespective of the color space being output. The gallery below shows that the behavior of the driver doesn't correlate in any way to the settings in the control panel. NVIDIA drivers seem to adopt two modes for the limited (16-235) and full (0-255) settings, one for global (desktop, photos etc.) and one for videos. Global mode is chosen to be limited (16-235) for all in-built resolutions and full (0-255) for all custom resolutions when in YCbCr mode with no way to change this (the gallery below shows correct dynamic range being chosen in RGB mode for still photos / desktop). The dynamic range for video and desktops are also different. Toggling the dynamic contrast enhancement box also seems to affect this setting. In addition, there is no way to specifically choose RGB Full or RGB Limited in the current drivers.

This dynamic range issue was apparently present in the Vista days, and fixed earlier. There appears to be a regression in the state of this bug recently, and we have been observing problems since May 2011 at least. A method to fix the issue has been outlined on Microsoft's official Windows community forums. It is disappointing to note that NVIDIA has still not fixed the issue despite the bug being a major annoyance for many HTPC users.

HTPC Aspects : Custom Refresh Rates HTPC Aspects : Decoding and Rendering Benchmarks
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  • HighTech4US - Wednesday, June 20, 2012 - link

    At least hen the GT240 was released it came in both DDR3 and GDDR5. Reply
  • UNhooked - Wednesday, June 20, 2012 - link

    I wish there was some sort of Video encoding benchmark. I have been told AMD/ATI cards aren't very good when it comes to video encoding. Reply
  • mosu - Thursday, June 21, 2012 - link

    who told you that kind of crap ?Please check the internet. Reply
  • Rumpelstiltstein - Thursday, June 21, 2012 - link

    Did this low-end offering really manage to pull off these kind of numbers? I'm impressed. Not something I would buy personally, but I would have no problems recommending this to someone else. Reply
  • Samus - Thursday, June 21, 2012 - link

    DDR3....ruined a perfectly good chip. Reply
  • Deanjo - Thursday, June 21, 2012 - link


    Really the only thing we don’t have a good handle on for HTPC usage right now is video encoding through NVENC. We’ve already seen NVENC in action with beta-quality programs on the GTX 680, but at this point we’re waiting on retail programs to ship with support for both NVENC and VCE so that we can better evaluate how well these programs integrate into the HTPC experience along with evaluating the two encoders side-by-side. But for that it looks like we won’t have our answer next month.


    Noooooo! Come on, post some benchmarks as it is right now. Some of us do not want to wait for AMD to get their VCE in order. People have been waiting for VCE for months and there is no valid reason to hold off NVENC waiting for their competitor to catch up. When and if VCE support comes out then run a comparison then.
    Reply
  • ganeshts - Thursday, June 21, 2012 - link

    NVIDIA indicated that official NVENC support in CyberLink / ArcSoft transcoding applications would come in July only. Till then, it is beta, and has scope for bugs. Reply
  • Deanjo - Thursday, June 21, 2012 - link

    So? That didn't prevent them benching trinity and it's encoding capabilities despite it all being beta there.

    http://www.anandtech.com/show/5835/testing-opencl-...
    Reply
  • drizzo4shizzo - Thursday, June 21, 2012 - link

    So... do these new cards still support HDTV 1080i analog signals for those of us who refuse to give up our 150lb 34" HDTV CRTs?

    ie. ship with a breakout dongle cable that plugs into the DVI-I port? If they don't ship with one can anyone tell me if they are compatible with a 3rd party solution? For it to work the card has to convert to the YUV colorspace. My old 7600gt *did* support this feature, but none of the new cards mention it...

    Upgrading my TV also means buying a new receiver for HDMI switching to the projector, fishing cable in walls, and all manner of other unacceptable tradeoffs. Plus monay.

    Thanks!
    Reply
  • philipma1957 - Thursday, June 21, 2012 - link

    I have a sapphire hd7750 ultimate passive cooled card.

    This card seems to be worse in every case except it is 1 slot not 2.

    The passive hd7750 is 125 usd this is 110 usd.

    I am not sure that I would want this until they make a passive version.
    Reply

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