Cross-post: http://thegreenbutton.com/forums/thread/170495.aspx. The discussion is about 2-3 second pauses in video playback using Xbox360 and Vista (in my case x64 Ultimate)
I have the same symptoms. I have more data:
The movie only shows the 2-3 second pauses during certain portions of the movie and it always shows the pauses in the same place. The video, in this case The Incredibles, has a section about 9:30 seconds into the movie, where a deliberately grainy black and white motif is used to represent archive footage in the movie so we realize it is a flashback. The artificial static over the whole screen appears to be more demanding for video bandwidth in the .wmv format. Apparently it doesn't compress as well, and thus requires 6x the bandwidth. After that section of the movie is complete, pauses stop.
Disk activity during this portion of the video increased disk i/o (.5MBps vs. 3 MBps) . Network activity shows a correlation. It jumps from a stochastic average of about 1.5Mbps to a very flat 7Mbps, where the primary offender is the ehshell.exe process. 6 x 1.5Mbps = 9 Mbps. Therefore the stream is being throttled by something to 7Mbps.
But by what? I went to the network controller and turned off QoS. It turns out Vista has a new way to throttle outgoing network traffic (pacer.sys). I believe pacer.sys is disabled by disabling QoS in the network controller. I did that and it had an effect, but not the desired effect. The network i/o now peaked well above 7Mbps. The effect was that the video would pause and stay paused until well after that section. It would then skip over the higher bandwidth portion of the video and return to normal.
For the record I tried the following test cases. In all cases the .wmv file is on the same hardware. Only #6 failed in all three sub-cases.
- Vista Ultimate x64 using Media Player.
- Vista Ultimate x64 using Media Center.
- Using file sharing on notebook using Vista Home Premium
- Using automatically loaded sharing under Media Player on said notebook.
- Using Xbox360 as extender to MCE 2005 x86 on same hardware as x64 machine
- Using Xbox360 as extender to x64 machine
- With Netgear GS108 Gigabit LAN switch only
- With D-Link DGL4300 Switch/Router only
- With Both switches in line (normal config)
Added Test Cases (2/25/2007). The same movie was played under some new circumstances:
- Same WMV file played using Media Video Blade works fine
- Same movie endoced as MPEG works fine (with ~11Mbps network throughput)
Here is my conclusion:
- Based on 1-6, the bottleneck is probably in the Xbox360 in handling WMV files.
- Based on 5/6, the bottleneck has to do with the Vista Media Extender client on the Xbox360.
By the way, I also tried the recommendations in Microsoft Knowledgebase article 929707. They did not help.
- BratE
MCE2005/VISTA x64 Ult
Intel D945 @4.5GHz
2x70GB RAID1
5x300GB RAID5
XBox360 MCX
MCE 2005,
MSI 945 Speedster mainboard (onbaord 1080p DVI, 5.1 audio),
Celeron M
Samsung 1080p native DLP
Yamaha RX-Z9 receiver/amp
Other components