Recently bought an R9 270x card and since I installed it there are 6 HDMI Audio devices in the Playback Devices control panel. The control panel and any other sound-related controls also take ages to load. I have tried uninstalling the drivers and rolling back, but the HDMI Audio devices appear after windows auto-detects the card.
I use my PC to play movies occasionally via HDMI to a 40" Toshiba Regza. Once the Playback Devices Panel is loaded and I can switch sound output to HDMI Audio Device 1 there are no issues with the sound.
I have had no issues with gaming or video playback but it is ridiculous having to wait for 5+ minutes for the panel to load to switch sound output.
Sapphire R9 270X Dual-X OC edition
Catalyst 13.11 Beta 9 - Tried: 13.11 Beta 8, 13.9
Windows 7 Ultimate 64-bit
Asus M5A97 LE R2.0 with AMI 1903 Bios
Main Display: Acer P223W connected via DVI-VGA adaptor
2nd Display: Toshiba Regza 40" (used only for watching movies) connected via HDMI
AMD FX-8320 (8 cores @ 3.7Ghz)
Crucial Ballistix DDR 3 1600 (2x4GB)
Western Digital 1TB HDD, Crucial M4 SSD 64GB
Creative X-FI extreme audio PCIe card (in non-conflicting slot)
I use BitDefender and Malwarebytes to keep my pc clean. All software is up-to-date and my HDD is regularly defragged.