Asus P5E-VM HDMI: A microATX C2D board for gamers?

POWER & HD VIDEO PLAYBACK TESTING

Our test procedure is designed to determine the overall system power consumption at various states (measured using a Seasonic Power Angel), and to test the integrated graphics' proficiency at playing back high definition videos. Standard HD-DVD and Blu Ray discs can be encoded in three different codecs by design: MPEG-2, H.264/AVC and VC-1. MPEG-2 has been around for a number of years and is not demanding on modern system resources. H.264 and VC-1 encoded videos on the other hand, due to the amount of complexity in their compression schemes, are extremely stressful and will not play smoothly (or at all) on slower PCs, especially with antiquated video subsystems.

We used a variety of H.264 and VC-1 video clips encoded for playback on the PC for testing. The clips were played with Windows Media Player 11 and a CPU usage graph was created by the Windows Task Manger for analysis to determine the approximate mean and average CPU use. High CPU usage is indicative of poor video decoding ability on the part of the integrated graphics subsystem. If CPU usage reached extremely high levels and the video skipped or froze, we concluded the board (in conjunction with the processor) failed to adequately decompress the clip.

Enhanced Intel Speed Step was enabled and Aero Glass was disabled during testing.

Video Test Suite

1280x720 | 24fps | ~6.1mbps

720p H.264: BBC's HD in Full Bloom is encoded with H.264. It features time-lapsed photography, mainly of various flowers blooming with vibrant colors and high contrast.

1920x816 | 24fps | ~9.9mbps

1080p H.264: Rush Hour 3 Trailer 1 is encoded with H.264. It has a good mixture of light and dark scenes, interspersed with fast-motion action and cutaways.

1440x1080 | 24fps | ~7.5mbps

WMV3 VC-1: Coral Reef Adventure trailer is encoded in VC-1 using the WMV3 codec (commonly recognized by the moniker, "HD WMV"). It features multiple outdoor landscape and dark underwater scenes.

1280x720 | 60fps | ~11.9mbps

WVC1 VC-1: Microsoft Flight Simulator X trailer is encoded in VC-1. It's a compilation of in-game action from a third person point of view. While the source image quality is poor compared to the other videos in our test suite, it is encoded using the Windows Media Video 9 Advanced Profile (aka WVC1) codec — a much more demanding implementation of VC-1.

At stock settings, the system power consumption reached almost 100W when both Prime95 and ATITool's artifact scanner were run concurrently. When undervolted to 1.100V, there was a significant reduction of approximately 20% at load. Underclocking also yielded some further power savings, though not nearly as dramatic. We can only imagine what numbers we would've seen if the board allowed us to go below 1.100V. Undervolting (if stable) is an easy way to keep the electric bill low and allows slower, quieter CPU and system fans to be used.

Video playback was excellent as none of the clips gave the test system any problems. The demanding WVC1 clip was also played with the system underclocked to 1.6Ghz and 1.2Ghz. At 1.6Ghz there was a moderate increase in CPU usage, but also a sizable decrease in power consumption. At this speed, it still rendered the video smoothly with plenty of headroom. Intel's slowest dual core processor happens to be clocked at 1.6Ghz, so in conjunction with a G35 motherboard, all of Intel's slower dual core processors are fast enough to play back the majority of H.264 and VC-1 videos adequately. At 1.2Ghz, the clip stuttered frequently and there were complete pauses in some spots. If underclocking, we recommend keeping the clock speed to at least 1.4Ghz for proper VC-1 playback.

COMPARING G35 and G33

It's not really a faceoff between chipsets, rather, it's one between specific motherboards. A chipset comparison would require many different board samples. However, it's interesting to compare this board against the Intel DG33TL reviewed last week, equipped with the earlier G33 chipset and GMA X3000 graphics.

The new Asus shows a slight improvements in video playback. Looking at the power consumption numbers we find that at idle there was only a 4W gap, but the difference was negligible when running Prime95. The most notable differences occurred during video playback testing, where power consumption was up to 8W higher. These results seem to indicate that the more advanced integrated graphics of the G35 chipset simply has a higher overhead.

During stress testing, both chipset heatsinks became very hot. While this was expected on the much smaller southbridge heatsink, it was more of a surprise on the much larger northbridge heatsink. This may be due, again, to the more advanced GMA X3500 graphics.