I'm running Windows 7 Media center on the following computer:
- Dell Studio XPS 8100
- Intel Core i7-870 CPU
- 8Gb Ram
- ATI Radeon HD 5770 with 1Gb GDDR5 memory
- 1 Tb Sata 2 HD
- Avermedia USB over-the-air tuner
- Blu-ray drive
I am using an over-the-air HD antenna, mounted outside.
Connected to a Vizio 55-Inch HD LED display via an HDMI cable.
I have had this setup for a year. I use it to record over the air HD programming for later viewing, NetFlix streaming and playing Blu-Ray using the ArcSoft Total Media Theater 5 plug-in to Media Center.
Up until one month ago, it did a beautiful job with this. Image quality was great and video was smooth.
Around the beginning of October things deteriorated. Video is now very choppy, especially when there is a lot of movement on the screen, such as football games. It is as if the frame rate is down to around 5 frames a second.
This occurs regardless of whether I am viewing live TV or playing recorded TV back or streaming NetFlix.
I know the antenna is fine, because when I plug the antenna into my TV's built-in tuner the video is fine.
I know it is not the Avermedia tuner, because streaming Netflix is also choppy on the PC. But when I stream Netflix directly on the Vizio (it is has a built-in Netflix app) it is fine.
Strangely, playing blu-ray through the Total Media Theater plug-in works fine. This has made me conclude that it is purely an issue with the Windows Media Center software, since the Total Media Theater software is working OK.
I have upgraded to the most recent video drivers. There is plenty of hard disk space left. There are no other applications using up CPU cycles. I have uninstalled all antivirus software.
Bottom line is that I can't figure out what caused the deterioration. The only thing I can think of is that maybe some automatic windows update change screwed things up. But when looking at historical updates I can't find any updates in the last month other than security updates.
If anyone has any other debugging ideas, I'd be grateful.