Quick Sync Technology
So far we have spoken of Sandy Bridge graphics core as the next evolutionary step from Intel HD Graphics used in Clarkdale and Arrandale processors. However, it does have something unique about it too and that is Quick Sync technology providing hardware acceleration of HD video encoding and decoding.
You may think there is nothing surprising about it. All GPUs from AMD and Nvidia have long been able to encode and decode video using CUDA or Stream/APP. Moreover, previous generation Intel graphics integrated into Clarkdale and Arrandale processors is also capable of accelerating video playback on the hardware level. However, Intel engineers used a completely new approach to this matter in Sandy Bridge. The thing is that all GPUs that have been out there so far use their default execution units, namely shader processors, to work with video. Quick Sync technology works differently: it implies that there will be specific execution units involved into the encoding/decoding process. In other words, Sandy Bridge graphics core has a dedicated video codec and video decoder besides the traditional execution units.
Of course, the use of utilitarian hardware resources instead of a software/hardware combination with CUDA or Stream is not a universal solution, which also increases the die size. But according to Intel, the advantages of this solution are overpowering. Firstly, Quick Sync delivers higher performance, and secondly, special hardware turns out much more energy-efficient.
So, Quick Sync consists of two components. The first one is hardware decoder used to accelerate the playback of video content in popular MPEG-2, VC-1 and AVC formats. This part of Sandy Bridge graphics core can take over the entire decoding process including motion compensation and loop-filtering. Most importantly, this is a multi-threaded decoder, i.e. it can decode video in several parallel threads at the same time supporting picture-in-picture mode, stereo 3D Blu-ray or MVC.
The second part of Quick Sync is a hardware codec performing the opposite operations. Unlike the decoder, the codec also utilizes the traditional execution units of the graphics core, although most of the encoding is still done by special logics. The codec supports today’s most popular AVC format.
As a result, Quick Sync technology as a whole allows speeding up video transcoding by decoding video stream in one format and encoding it right away into another. This is a very important and timely feature of the new Sandy Bridge processors. Video content transcoding operations are very popular even among home users, as video content hosting services as well as increasing popularity of high-performance mobile devices capable of playing multimedia content become more and more widespread.
As we know from our previous processor test sessions, video transcoding involving traditional processor capacities is pretty much the most resource-consuming operation, which takes a lot of time and uses a lot of power. With Quick Sync technology we can not only speed up this process, but also free processor cores for simultaneous execution of other tasks.
Of course, Quick Sync technology must be supported on the software level. But Intel didn’t forget about it and today there are a lot of popular utilities for video transcoding that can utilize effectively special units in the new Sandy Bridge processors. And the examples are right in front of us: new versions of ArcSoft MediaConverter, Corel DVD Factory, CyberLink MediaEspresso, Movavi Video Converter, Roxio Creator and other applications already support new media functionality.
Once Intel integrated new codec and decoder into their graphics core and ensured widespread support from software developers, they managed to outplay AMD and Nvidia who offer slower video transcoding involving their shader processors. However, we do not know if isolation the codec and decoder into individual hardware units will ever grow into a new trend. Maybe Quick Sync technology will simply encourage other GPU developers to optimize their transcoding algorithms using CUDA and Stream/APP.
However, Intel slightly spoiled the good impression from Quick Sync. It was a big mistake on the developers’ part to place encoding and decoding units into the graphics core. Video transcoding is something you would do independent of the type of graphics, integrated or discrete, in your system. But unfortunately, you won’t be able to use Quick Sync resources in Intel P67 based systems. Mainboards with this chipset will disable the integrated graphics core and thus you lose access to this promising technology. So, you will only be able to take advantage of hardware acceleration in the Intel graphics processor in those systems where the integrated Sandy bridge graphics core is working.