AMD's Trinity : An HTPC Perspectiveby Ganesh T S on September 27, 2012 11:00 AM EST
HTPC enthusiasts are often concerned about the quality of pictures output by the system. While this is a very subjective metric, we have been taking as much of an objective approach as possible. We have been using the HQV 2.0 benchmark in our HTPC reviews to identify the GPUs' video post processing capabilities. The HQV benchmarking procedure has been heavily promoted by AMD, but Intel also seems to be putting its weight behind that now.
The control panel for the Trinity GPU retains the host of options from earlier Catalyst releases. We used Catalyst 12.8 in our testing.
HQV scores need to be taken with a grain of salt. In particular, one must check the tests where the GPU lost out points. In case those tests don't reflect the reader's usage scenario, the handicap can probably be ignored. So, it is essential that the scores for each test be compared, rather than just the total value.
The HQV 2.0 test suite consists of 39 different streams divided into 4 different classes. For the Trinity HTPC, we used Cyberlink PowerDVD 12 with TrueTheater disabled and hardware acceleration enabled for playing back the HQV streams. The playback device was assigned scores for each, depending on how well it played 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 from HQV.
Blu-rays are usually mastered very carefully. Any video post processing (other than deinterlacing) which needs to be done is handled before burning it in. In this context, we don't think it is a great idea to run the HQV benchmark videos off the disc. Instead, we play the streams after copying them over to the hard disk. How does the score compare to what was obtained by the Llano and Ivy Bridge at launch?
In the table below, we indicate the maximum score possible for each test, and how much each GPU was able to get. The HD4000 is from the Core i7-3770K with the Intel 126.96.36.19996 drivers. The AMD 6550D was tested with Catalyst 11.6 (driver version 8.862 RC1).
|HQV 2.0 Benchmark|
|Test Class||Chapter||Tests||Max. Score||AMD 6550D (Local file)||Intel HD4000||AMD 7660D|
|Video Conversion||Video Resolution||Dial||5||4||5||5|
|Dial with Static Pattern||5||5||5||5|
|Film Resolution||Stadium 2:2||5||5||5||5|
|Overlay On Film||Horizontal Text Scroll||5||5||3||5|
|Vertical Text Scroll||5||5||5||5|
|Cadence Response Time||Transition to 3:2 Lock||5||5||5||5|
|Transition to 2:2 Lock||5||5||5||5|
|Multi-Cadence||2:2:2:4 24 FPS DVCam Video||5||5||5||5|
|2:3:3:2 24 FPS DVCam Video||5||5||5||5|
|3:2:3:2:2 24 FPS Vari-Speed||5||5||5||5|
|5:5 12 FPS Animation||5||5||5||5|
|6:4 12 FPS Animation||5||5||5||5|
|8:7 8 FPS Animation||5||5||5||5|
|Color Upsampling Errors||Interlace Chroma Problem (ICP)||5||2||5||5|
|Chroma Upsampling Error (CUE)||5||2||5||5|
|Noise and Artifact Reduction||Random Noise||SailBoat||5||5||5||5|
|Compression Artifacts||Scrolling Text||5||3||5||5|
|Upscaled Compression Artifacts||Text Pattern||5||3||3||3|
|Image Scaling and Enhancements||Scaling and Filtering||Luminance Frequency Bands||5||5||5||5|
|Chrominance Frequency Bands||5||5||5||5|
|Resolution Enhancement||Brook, Mountain, Flower, Hair, Wood||15||15||15||15|
|Video Conversion||Contrast Enhancement||Theme Park||5||5||5||5|
|Beach at Dusk||5||5||5||5|
|White and Black Cats||5||5||5||5|
|Skin Tone Correction||Skin Tones||10||7||7||7|
We did some quick tests to ensure that all the post processing steps available for Blu-rays were also available for local files using MPC-HC's EVR renderer. AMD deserves kudos for being the only GPU vendor to get the local cadence detection (with respect to the shredding of overlay text) correct. In addition, they are the only ones to offer mosquito noise reduction as an option in addition the usual denoising setting. The chroma upsampling issue we noticed with the Llano is no longer an issue. With a score of 199, the 7660D with the Catalyst 12.8 drivers becomes the best performer on the HQV front. It is possible that the 7750's scores have also improved with these drivers, but we will take a look at that in another piece.
However, this doesn't mean that AMD's drivers are perfect. By default, the EVR / EVR-CP renderers rely on the drivers to supply the correct video levels to the display. As the screenshots below indicate, the meanings of full and limited seem to be interchanged.
Dynamic Range Set to Full for Video Playback (background)
Dynamic Range Set to Limited for Video Playback (background)
Setting the dynamic range to Limited (16-235) exposes black levels in the range 0-15 and 236-255, while setting it to Full (0-255) actually clips the color levels in the video in the background. This was one of the more obvious bugs that we encountered in our review process.