Thank You!
2. Well, I believe cheapest way is to disconnect one of my screens on DVI port and to connect it via another cheap mini DP-VGA adapter, after that I believe HDMI port will be free to use.
3. Basically my max res at 120Hz is 1024x768 then? Can you please tell me how good is 3D with your projector at 1024x768 for example?
Also, what if I'll buy second projector in the future and will rotate both to portrait mode and do 2x1 eyefinity (1024x768 x 2) with total res 2048x1536. Will it work?
2. Yes, but that'll require swapping around cables a lot.
3. Native resolution is typically the maximum S3D resolution possible on projectors. Non-S3D resolutions can scale though. You can do 1920x1080 60hz but it won't let you do 1920x1080 120hz.
The thermal properties of projectors are problematic. They're only designed for landscape orientation. You could set your projector to high altitude mode and/or use an LED based projector though. I specifically will not recommend projectors in portrait mode though. Problem with LED based projectors is the lumens ratings are not good at all. I would never suggest using anything under 1200 lumens. I prefer the 2500 lumens on my projectors. 2048x1536 is 2x2L. That is not a portrait resolution. You'll need an edge blending software option in order to properly do it. Frankly, I suggest just using 2 1080p projectors instead of 4 1024x768. The more projectors you use the more bulb cost on consumables and the more persistent alignment issues you need to address on a constant basis.