Minor Recording/Streaming operation

I'm half the "Worship Technology" department at my church. It has been long discussed integrating cameras into ProPresenter, recording sermons, streaming to offsite locations. So I asked the budgeteers for a Decklink Studio 4K and they obliged me. Got it yesterday and threw it in our "projection computer", windows 7, i5, plenty of ram, GTX 660 driving all the displays it can stomach. Our only input right now is a consumer handcam pushing 1080i59 out HDMI, works really well for the little we do with it. Took me 4 hours to go from knowing nothing of this kind of hardware to working everywhere but I got it. So here are my noob questions.

The feed from the card is either 1080i or SD. The software I use (propresenter and livestream) refused to work until I figured that out and fed the SD to them. I understand the 1080i feed is a bit to rich for livestream and PP has it's own hangups but can this card not take it to a step in between? Downgrade to 720i/p instead of all the way to SD? SD hurts my eyes.

Is there no way to feed multiple programs at once? Like if I wanted to record and PP live at the same time.

What is the favored HDD solution for recording 1080i59? I dropped frames every time I tried despite a somewhat bored processor. So I figured trying to run PP displaying a video and recording 1080i at the same time was a no go on a mid tier SSD. I'm looking at 550/480 R/W SSD and could probably swing 2 in Raid 0 if that's not fast enough but I want to do it in one budget request. Is 480 write fast enough? Or am I going to have to buckle down for some real spending?

Thanks for the help.

Blackmagic capture cards do not have a built-in HD scaler. That means in order to capture in 720p your camera would have to output 720p. Most consumer cameras will only output 1080i and therefore the capture card can only recognize 1080i.

Once a program "locks" onto a capture card, no other program can access it. That's why the majority of live streaming services will both stream and record at the same time (no other program would be able to access the feed).

If you are trying to record using Media Express make sure you are not recording in uncompressed format. HD video uses up so much data, almost no non-solid state drives can keep up. Recording uncompressed uses very little CPU, but lots of i/o to the hard drive. Recording in a compressed format (like MJPEG on windows, or ProRes on Mac) uses up a lot of CPU but less i/o to the disk).

That being said, most people uses a separate computer for playout (ProPresenter) and streaming. Having the the projector feed go offline because of a bug with the video capture or live stream is not great.

Alright so I guess I will have to find a suitable scaler. I like the Teranex products but it's a little out of reach.

When I saw that "locking" thing I pretty much arrived at the idea that I'd need a dedicated streaming computer. I have a few lying around, I'll see which works well for that.

Well I put two platter drives in Raid 0 and got 250-260MB/s write and it seemed to do a good job recording 1080i59 8-bit YUV but you're right the end file was MASSIVE. I might be able to throw it though a converter after the fact and convert it to H.254. Then when I stand the steaming operation up I'll just steal livestream's recording instead of doing the massive uncompressed recordings.