For MPEG-2 playback tests, we ran The Matrix DVD, a personal favourite of mine on each system with Hardware Acceleration enabled to check for smoothness of playback as well as CPU usage during the test. The result was with 30 minutes of playback and the CPU utilisation is the average.
Both setups played MPEG-2 video flawlessly; there was no dropped frames seen and the audio was sync'ed through the whole process. So, we consider it a success for both platforms.
On the CPU usage side, both systems managed to run around the same 15% with the VIA and 9800GX2 going down to around 11% thanks to the dedicated engine on the graphics card taking the decoding away from the IGP and system memory.
Playback for MPEG-4 was again done with the Matrix, only encoded down to MPEG-4 DIVX 6.8 codec. 30 minutes was the time run. Smoothness of playback, audio sync and CPU usage are the keys here once again.
Here is where VIA gets a leg up on Intel, While both systems were able to playback the MEPG-4 video without jittering or audio sync problems, the VIA CPU never broke 25% usage, where the Atom was over 60% usage, this meant that if we tried to multi task, it would sometimes lag up the video for a second on Atom, VIA had no problems opening a Web page or loading Email.
HD Video Playback
This is the big one for the platforms. We downloaded a random 720p video to test out using Media Player 11. Again, quality of video playback, audio sync and CPU usage are the big things to focus on here.
A big win to Nano here. Atom was lagged all the way through; there was audio sync problems and video jitters. In fact, it was more like watching a slideshow of pictures on Atom with its CPU usage going right up to 98% where VIA managed to run at no more than 60% without a hitch.