Hmm! I spoke too soon when I said that installing the HD 5450 media card in the new machine went well. Towards the end of the software installation process I settled down to watch a DVD using 7MC (Windows Media Center for Windows 7) and it was almost unwatchable. Every five or six seconds the picture would skip forward a frame although the sound was fine.
This skipping/jitter/judder/stutter was restricted to 7MC. Play the same DVD in WMP (Windows Media Player) or TotalMedia Theatre 3 (TMT3 from Arcsoft) and the picture and sound was silky smooth.
Previous experience has informed me that I don't need a whole bunch of codecs and other paraphernalia to perform the limited set of tasks I need my Media PC to do and in any event 7MC uses Media Foundation codecs rather than DirectShow and I'm using 64 bit Windows anyway so little is available. Even so I gave it my best shot spending about three days trying to tweak the ATI Catalyst drivers and turning various bits of Windows off. I even unloaded my security suite (Kaspersky) as a test as the Windows performance monitor showed CPU usage spiking up to about 6% roughly in time with the frame skipping.
To cut a very long (3 days) story short the culprit was a cunning piece of software supplied with my Asus P7H55D-M EVO motherboard, namely ASUS EPU (v6) also know as EPU-6. It can dynamical underclock or overclock the CPU depending on how hard the software asks the CPU to work. In the context of a Media PC the CPU, a Coreâ„¢ i5-661 in my case, is hardly awake so the idea of using such software is to perform a lazy person's 5% underclock reducing heat production and consequently fan noise.
I had EPU-6 set up to automatically adjust the CPU speed so I assumed that the speed variability was causing the 7MC DVD playback problem but even setting EPU-6 to command a fixed underclock didn't help. Shut EPU-6 down, however, and 7MC started producing the same smooth video that WMP and TMT3 were able to do all along.
Before you decide that EPU-6 (or 7MC) is a load of rubbish it's also a fact that I run it on my main PC here and 7MC has no issues on that machine. The main differences are a more powerful CPU and a high end Nvidia graphics card. The implication is that there's bad karma when 7MC, EPU-6 and an ATI HD 5450 graphics card are asked to play nicely together. I may
have also seen the same problem with the motherboard's integrated (Intel) graphics but I had already decided to get the ATI card so I wasn't really paying attention at that point.
Hopefully this post will be of help to anyone Googling
in search of an answer to stutter on DVD playback using Windows Media Center. With my problem solved I'm more and more impressed with the HD 5450. It has plenty of horsepower in an HTPC context, it inserts sound reliably into the HDMI output (TMT3 will play Blu-rays and push out Dolby Digital TrueHD sound) and picture quality is superb whether from genuine HD content or from upscaled DVDs. And best of all it uses less than twenty watts and doesn't need a fan provided your case is well ventilated. Recommended.
On reflection I don't think the conflict was just restricted to DVD playback as the "Visualisations" available when playing, say, a radio station (mcShoutcast) also run more smoothly. It looks as though EPU-6 was compromising 7MC's general rendering speed.
And now that the build is complete and I don't need to use any of the Asus "tools" I've uninstalled AI Suite and PC Probe II for good measure.