Multiple ATI TV tuners not playing nicely together

[null_pointer_us]

I own a 550 Pro PCI and a 650 Combo PCI-E. They work separately without issue for analog TV. However, when both are in my system, there are some weird problems:

1. The card that's installed second consistently has greatly reduced volume. Odd.

2. The 550 occasionally produces green/blocky video that stutters to the point that shows are unwatchable. Loud audio (e.g. gunshots in CSI) and panning seem to cause this green/blocky artifacting.

3. Low pitch audio (bass) is extremely distorted, as if I was somehow playing back through $10 speakers. I've tried a variety of audio adjustments in my sound card (ALC88x) control panel applet and the audio mixer, but no go.

4. SageTV randomly crashes on playback (which interrupts my recordings). After completely uninstalling Catalyst 8.8 and then installing 8.9, the crashing problem seems to have disappeared.

5. During source setup, SageTV incorrectly offers a "Digital TV" input option for both sources, even though the 550 doesn't support ATSC/QAM.

I was using the ATI MPEG decoders for audio and video, but the SageTV MPEG decoders have the same problems with low volumes, video artifacts, and distorted audio. This points to corrupted source video instead of just buggy playback.

Any thoughts?

My guess is that ATI's unified A/V stream drivers try to force both cards to use the same settings -- either both act like 650's or both act like 550's -- and this causes the odd compatibility problems (above).

I recently did this clean installation of Vista x86...

[big poppa pump]

Two ATI TV cards on the same system is a major headache. I used to use the 550pro and 650pro on my earlier MCE machine and I used to get constant BSOD's. I actually contacted ATI tech support regarding this and they themselves recommended not to install 2 ATI cards on the same machine. I switched out the 550pro with the Hauppauge 1600 and never had any problems whatsoever after that.