PureVideo & WMV-HD Acceleration
Windows Media Video 9 Acceleration: Microsoft's Windows Media Video 9 (WMV9) HD format was accepted by the SMPTE HD-DVD consortium as a new HD format. THe Windows Movie Maker software, which comes bundled with Windows XP, makes it easy for consumers to edit and save their favorite videos. These videos are saved in the .WMV format. NVIDIA's GeForce 6 Series GPUs and now the GeForce 7800 GTX are the first family of GPUs from NVIDIA to include dedicated hardware to accelerate the playback of WMV and WMV-HD content for fluid full frame rate video even on systems with entry-level CPUs. Previous generations of NVIDIA GPUs were not able to support WMV9 decode acceleration, so often times HD WMV9 content would drop frames when being played back on NVIDIA hardware.
To document CPU utilization when playing back WMV HD content, we used the performance monitor built into Windows XP. Using the data provided by performance monitor, we created a log file that sampled the percent of CPU utilization every second, while playing back the 1080p version of the "Living Sea" video available on Microsoft's WMVHD site. The data was then imported into Excel to create the graph below. The graph shows the CPU utilization for the GeForce 7800 GTX in an un-patched environment, as your system at home may be configured right now, and patched using the DXVA WMP10 update posted on Microsoft's Web site a few weeks back (Update Available Here). The GeForce 6800 Ultra and Radeon X850 XT Platinum Edition were tested with the patch installed.
|Average CPU Utilization (Athlon 64 FX-55)|
|GeForce 7800 GTX (Unpatched) - 38.81%||GeForce 6800 Ultra - 43.52%|
|GeForce 7800 GTX (Patched) - 33.88%||ATI Radeon X850XT PE - 36.18%|
Thanks to the G70's improved PureVideo dedicated video processor, the GeForce 7800 GTX has much lower CPU utilization during HD video playback than the GeForce 6800 Ultra, which didn't perform as well as NVIDIA had wanted in this category (WMDHD acceleration was "fixed" in the 6600 and newer GPUs though). The Radeon X850 XT Platinum Edition fares a bit better here, but with a patched system the GeForce 7800 GTX used the fewest CPU resources of the bunch. We should also note that the GeForce 6800 Ultra suffered from some visual anomalies in this test that resulted in some strange colors on-screen. We're uncertain whether these anomalies had an impact on performance, but the end result should still be the same. The 7800 GTX is simply better then the 6800 Ultra when it comes to HD decode acceleration.
NVIDIA's PureVideo technology isn't just about HD decode acceleration though. We've covered the other main features and benefits of PureVideo in this article, but there a few more things we should mention here as well. Since the initial introduction of PureVideo, NVIDIA has added a few more features to its video processor. The GeForce 7800 GTX, when coupled with the new Rel. 75 drives, now offers High-Definition Spatial-Temporal De-Interlacing, Inverse 2:2 Pull-down correction (PAL), and playback of high-definition ATSC and DVB MPEG-2 transport streams. And by Christmas, PureVideo should incorporate H.264 acceleration as well. NVIDIA is also working directly with ISVs such as Cyberlink and IVI to power its H.264 decoders, so users won't be forced to solely use NVIDIA's proprietary decoder software to enjoy the benefits of PureVideo.