OK, so I'm having the same problem, as I presume many are these days. Hard to imagine SOMEONE has not solved this yet.
Here's the issue, recapped a bit but in terms that I think make more technical sense than some outlines.
Monitor 1 is an HDTV capable of full HD - 1080p display.
Monitor 2 is a display with a maximum resolution something less than 1920 x 1080 - it will not display full 1080p. In my case, I'm working with an old-school TV on a scan converter, so in theory the max "resolution" is 640 x 480.
I want the same output on both screens. This is called "clone" or sometimes "mirror" mode. I do NOT want to "extend my desktop" to the second screen, because I want whatever is playing back on Monitor 1 to also be playing back on Monitor 2.
With every video card I've tried (ATI and Nvidia), if I "extend" my desktop to Monitor 2 I can then change the resolution of Monitor 2 to whatever I want, completely independently of the settings for Monitor 1. In this mode, however, whatever I'm showing on Monitor 1 does NOT show on Monitor 2. Sure, I can drag it over there, but it's "either/or", not simultaneous on both.
On the other hand, if I "clone" Monitor 1 to Monitor 2, I get exactly what I want - the same content on both screens - but since that content is being displayed at 1920 x 1080, only a small portion of the content is visible on Monitor 2... Not watchable.
I've tried Ultramon, it's great, it DOES what I want, however it is too resource intensive for the machine. It makes the video playback jerky and generally unwatchable for a normal TV or movie watching experience.
Secondary issue - just throwing this into the picture because it may be useful for someone else reading this with the same problem. Monitor 1 is connected via HDMI with the audio travelling on the same HDMI cable/interface. Monitor 2 is connected using VGA out going through a scan converter - which means NO audio is associated with it.
To get audio to the second monitor I use a program called VirtualCable, which allows me to send the same audio to two different audio interfaces - one being the HDMI audio, the second being the audio card built into the machine's motherboard. Only downside to that is a slight delay in audio, but I've found if I set that to 150ms in VirtualCable it's not noticeable to most people.
So... What I would LIKE to do is find a way to send the same desktop view (i.e. "clone" it) to two monitors, one with 1920 x 1080 resolution, the second with 640 x 480.
At the same time, as a side effect, if this was also possible in a way that sent the same AUDIO to both video interfaces that would be wonderful...
Options I can see...
1) A single video card with two monitor outs, that allow independent configuration of both outputs for resolution. If one output was HDMI and the other "something analog" (analog VGA, composite video, S, etc) that would be great for MY purposes, but just two HDMI out's would work if it had to - I can get an external HDMI to analog converter.
2) Two video cards that would then allow the same thing as above.
3) An external device that would allow me to take a single HDMI out from the video card and "split it" into two HDMI signals. This would then require me to have yet another external box, to convert the second HDMI video and audio into analog signals for the second monitor, so it would be ideal if this device not only split the HDMI out but also allowed for one of those split signals to go out HDMI and the other to go out in some form of analog video and audio, but how much can one ask for?
Am I missing something here, has anyone found a solution for this?
And, I've got to point out, external devices (or internal video cards) that cost several hundred dollars are generally not an option for me....