I have a Radeon 4870 in my MacPro - so I got a DVI/HDMI adaptor and I have run a HDMI cable into a HD TV. My monitor is plugged into the other smaller port. Should I get an output to the monitor and TV at the same time? I only get an output to the monitor, if I unplug the monitor I then get an output to the TV. Is there a setup I have missed? or is this expected behaviour?
Check your display settings - it sounds like mirroring is turned on, and the DVI-HDMI connection will only support a small number of resolutions. like 1080x1920.
FWIW - this is not a good way to get a video output on a TV, as cheap an option as it seems - and you may have considerable problems with it, AS IT WILL NOT display a correct raster and image. I strongly recommend purchasing one of the cheap HDMI output options (Blackmagic Intensity springs to mind - very affordable) that is actually supported as a video output in FCP. You will be amazed by the difference.
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