Decklink Quad and delay

I am curious with its bypass feature if the quad can capture video and allow to be processed by a program on a computer and output each input in real time (0 delay) without processing. Basically just a capture and bypass with no delay. The specs say it will bypass in the event of a system failure but it doesn't say if this functionality can be used in conjunction with normal capturing.

From my experience, the bypass output work even capture process (program) fails or crashes because loop-thru relays remains closed..

Yes but does any delay get introduced at all from input to output?

Loop-thru means signal is passed without any processing, so again that means 0 latency. Basically there's relay that physically connects input on output every time when driver starts capture process on selected channel.. At least that's how I understood it regarding black magic quad card.. Maybe someone from BM tech guys can confirm this.

Thats also what I assume, but at $950 I don't want to assume too much about the card's abilities. The wording of the feature is somewhat unclear as it only references a catastrophic failure and not normal operations and it implies that something changes when a failure occurs. I just want to make sure that I hear it from someone who knows for sure that it does indeed operate this way.

I agree with you. Best way is that if you can to borrow one from someone and test it before you buy it, that's how I ended with two of them, but only when I had one for a week test.. Check with your distributor and ask politely.