One of the biggest things which has been a constant annoyance for me with a HTPC of late has been the gradual drift of audio getting out of sync with video. The problem always seemed to be inconsistent and I could never narrow it down to one particular thing.
Well tonight it seems like I may have had a breakthrough, and it looks like the culprit was the Realtek HD Audio Manager. It was suggested that you should disable this service starting up when Windows starts, to see if that resolved the problem.
To do this you want to;
1. Go in to the desktop mode
2. Right-click on the taskbar and bring up the Task Manager
3. Go to Startup Tab
4. Look for the Realtek HD Audio service, right click the service and select Disable.
5. Restart the PC
I didn’t think my computer was even using Realtek for the audio as it was running through the ATI card on HDMI, but it was there and it was running. I disabled the service, and then restarted the machine, and everything looked great, and still sounded the same. I subsequently tested multiple video/audio sources including iTunes and Hulu and the sync problem seemed to be solved. I was also previously running the monitor at a refresh rate of 24 Hz as that seemed to have the least issue, but as everything was working ok, I pumped it back to the preferred 60 Hz, and lo and behold the audio and video still remained in sync.
I am going to monitor it for the next couple of days, but for now all seems to be running great… happy days for this HTPC owner.
So if you are running a HTPC with Windows 8.1 and happen to have the Realtek HD Audio Manager running as a start up service, try disabling it and see if that has a positive effect on your setup.