AMD Radeon HD 7970 Launch Review

Product: AMD Radeon HD 7970 Video Card
Company: AMD
Author: James Prior
Editor: Charles Oliver
Date: December 24th, 2011

Media Feature Updates

The AMD Radeon HD 7970 card adds two new media features, Fast HDMI and Discrete Directional Audio. The AMD Radeon HD 7900 is the first GPU to simultaneously output multiple independent audio streams - each audio connected display possesses its own audio output stream, and applications moved from display to display have their audio follow them.

Fast HDMI allows the Radeon HD 7900 series to support 3GHz HDMI with frame packing - upgrading from the HDMI 1.4a specification of 24 packed frames per second at 1080p per eye to 60 frames per second per eye, increasing performance for Stereo3D gaming. This also allows the HD 7900 series to support the next generation of 4K resolution displays which can use a single HDMI 1.4 3GHz or DisplayPort 1.2 High Bitrate 2 connection, rather than quad-DVI or dual DisplayPort 1.1 connections.

The audio capabilities are unchanged from Cayman, with support for Protected Audio for Blu-ray playback as well as DTS HD Master Audio and Dolby TrueHD. MST hubs are due this summer (where have we heard that before?) allowing the 6000 and 7000 series to become 6-display capable, and reducing the DisplayPort enabled monitor requirements.

The UVD is unchanged from Cayman, still UVD 3 but some new dedicated hardware has appeared - the Video Codec Engine (VCE). This is used for GPU accelerated encoding to H.264 HD video codec, and is operated in either full fixed encode mode or a hybrid mode in conjunction with compute running on the Radeon cores. One of its more exciting applications is taking the rendered frame and encoding it for use with WiDi - wireless display technology.

GCN architecture supports new AMD instructions that will be useful for video processing, accelerating sum of absolute difference (SAD) operations. These Quad SAD (QSAD) operations can offer a 48x speed up in some type of image analysis and processing, and will be leveraged by software from Sony, Corel, Arcsoft and Cyberlink.

QSAD can also be used to improve the performance of AMD Steady Video, in Steady Video 2.0 the Radeon HD 7970 can offer a 10x speed up over CPU based motion estimation.

Also new to Steady Video 2.0 is support for non fullscreen content, interlaced video content, and a demo mode so you can see the effectiveness of the steadiness you are applying.

In use, AMD has simplified the Vision Engine Control Center to make post processing and video playback enhancement controls simpler to use. They are quite effective in delivering a crisp and image for locally stored or streamed content, using a variety of applications. The UVD and shader accelerated processing effects let you get a higher quality image at the same power use as CPU based improvements would, with typically more granular flexibility than paid commercial software. Due to our use of a non-AMD based system, we can't evaluate Steady Video 2.0.

Testing using the 'slices' test video shows the vector adaptive deinterlacing still performs excellently, even with post processing added, allowing for a smooth and high quality image.