I am about to do a new build for a video mixing and recording system. I would love any input on some questions that i have not been able to find out with my current hardware and trial. To make it easier I tried to put a dash in front of each question.
I have a classroom that I plan on building a custom computer for, hardware is not a concern for the most part.However I will have at least 16GB of RAM, so question 1:
-Does vMix use all of the ram in the 64-bit system?

I will be building the computer with 4 HDMI inputs, 2 SDI inputs and 2 HDMI outputs(excluding video card for my two screens). My concern is about using two HDMi outputs to venue screens in addition to the two screens I will be using for normal computer use. The two HDMI outputs will be running all the time each from one of 4 HDMI input computers which I assume will not be a problem, as i might need to switch those during the session
-Can I use with 2 video out from vMix each with different sources while running dual screens off the video card for PC use?
-Am I able to record the two HDMI outputs at the same time, even if using a lower bitrate(since it is mostly powerpoint)

The reason my computer will have 2 SDI inputs is for both cameras to be brought in, and then streamed out to a Adobe Connect Meeting. the camera will never be outputted to the venue screens.
-will vMix be able to handle one stream encode with embedded audio while also doing all the above recording and mixing?

-And the final thing that concerns me that I can think of right now, is that my courses are 8 hours long, with 2-2.5 hour constant stretches wiht a 10 minute break in between, can anyone forsee any issues there?

I really like the look of vMix and its feature set so am working on speccing up a PC to run it (2u rack jobby), 8Gb RAM.

Question on the screens front - if I get a standard video card (for the flatscreen to control it - e.g. an Nvidia one with 1gb ram onboard), then something like a Black Magic Design Intensity to handle the HDMI in/out (1 of each) + analog inputs, will vMix use the processing on the Black Magic or NVIDIA cards?
And is it a combination that'll work, as I don't want to invest about £1k (incl 4tb WD Black drive) in a machine to find it won't be happy with this mix. Input(s) will be 1 HDMI for now + one or two SD now, output on VGA as I don't own a second HDMI projector at the moment.