XFX 8600GT and 8600 GTS XXX Edition Video Cards

The Second Generation Pure Video HD Engine

The GeForce 8600 GT and 8600 GTS both feature NVIDIA’s second generation Pure Video HD engine, making it the world’s first and only GPU to provide 100% offload for H.264 decoding. Current PCs require both a high end CPU and high end GPU in order to reliably decode and playback all types of HD content. With the GeForce 8600’s new Pure Video technology, HD playback can be done on nearly all PCs.

A new video processor (VP) block provides more advanced video post processing to improve overall video quality. A new integrated bitstream processor (BSP) allows the 8500 and 8600 GPUs to perform full HD decode. They are the worlds first video processors to offload from the CPU 100% of Blu-ray and HD DVD H.264 video decoding, enabling playback on mainstream CPUs and providing unsurpassed movie picture quality and low power consumption. PureVideo HD support for Vista is available now for GeForce 7 and 8 series GPUs. PureVideo HD support for the 8500 and 8600 GPUs under Windows XP is expected in June 2007.

The Video Processor 2 (VP2) is designed to accelerate the decode of the most advanced video codecs including MPEG-2, VC-1, and H.264 at high bit rates, up to 40Mbps in the case of BD. The Bitstream processor (BSP) is specially designed to accelerate H.264 entropy coding schemes known as Context Adaptive Variable Length Coding (CAVLC) and Context Adaptive Binary Arithmetic Coding (CABAC). The BSP is key to the CPU offloading that takes place on the GeForce 8600 series. Also included on the 8600 series is the AES128 engine that is used to accelerate the decode of the AES128 encryption protocol to support video content security schemes for players and operating system requirements. The AES128 engine ensures both the security and integrity of the video content. This all boils down to giving the end user something that NVIDIA calls the ‘best HD experience’ available on the market today.

To help show how the new video engine dramatically reduces CPU utilization, NVIDIA provided Legit Reviews with a couple slides that show CPU Utilization when doing H.264 decoding with actual Blu-Ray and HD DVD movies on an Intel Pentium 4 531 Processor with an ATI Radeon X1950 Pro versus the NVIDIA GeForce 8500 GT and then with nothing more than the CPU. When using the ATI Radeon X1950 Pro and the CPU the performance tests showed that 100% of the work was done by the CPU. With the NVIDIA GeForce 8500 GT it shows the CPU only helping out with ~30-45% of the work, while the GPU handled the rest.

NVIDIA also provided a slide that compares the faster GeForce 8600GTS to the older GeForce 7600 GT on an Intel Core 2 Duo E6400 based system. Here it shows that the Pure Video Engine in the GeForce hows that decoding these HD titles took anywhere between 80-100% of the CPU’s resources. The 7600 GT, with the standard Pure Video HD enabled, was able to reduce the CPU utilization down to about 60%. With the second generation Pure Video HD engine enabled the CPI is almost entirely free to do other things as CPU utilization was found to be roughly 20% on the GeForce 8600 GTS.

It’s obvious that the second generation Pure Video engine does a great job at decoding video and nearly takes the CPU out of the equation for HD playback. Eventually all of the decoding could take place on the GPU, so it’s highly possible that CPU utilization will be even lower on the next GPU’s that are in the works now. Currently, Pure Video HD acceleration for the GeForce 8600 GTS and GT is ONLY available for Windows Vista. Pure Video HD acceleration for Windows XP is expected to be available in June 2007.