Active Silicon x4 PCIe card is the best option:
AS D10 PE4H (single SD/HD-SDI input)
AS D20 PE4H (dual SD/HD-SDI input)

(1 lane SDI cards are old and being discontinued)
LFG composite card still available:
4 input composite, 1 lane

All work in Sonnet Echo Express range of Thunderbolt 2 Expansion Chassis
Magma and other TB2 chassis also work

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