Im thinking about buying the Sonnet iiie and combining a Decklink Quad 2 and perhaps a Decklink Quad HDMI recorder. Does anybody have any experience with this combination? Is it stable?

Thanks

Of note, Thunderbolt 3/4 has the equivalent bandwidth of a PCIe x4 lane and so using a x8 card like the Decklink Quad 2 will have "limited" results (will be fine for up to 4 full HD sources, but more than that will start to exhibit issues).


Ice

PCIe 3.0 x 4 yields 3.94 GB (Gigabytes) per second, or 31.52 gb/s (gigabits per second) bandwidth.

Eight channels of HD-SDI from a capture card would require a bandwidth of 1.45 gigabits x 8 = 11.6 gigabits per second, plus a little overhead.

Like Richard (Raugert), I have a ASUS laptop with the Sonnet Express IIIe, but with 2 x Decklink Duo 2 cards, and there are no issues,
plus the advantage of full size video BNC connectors and some redundancy should one Decklink card fail.

Keep in mind that in some computer systems, the Thunderbolt port may be shared with other peripherals internally within the computer.
ie. a SATA or NvME drive, graphics card etc.

This will affect the bandwidth available to the thunderbolt port.
Check your motherboard manual for more information.

Thanks!

Also thinking of doing this with 2 4xSDI Duo and an 4xHDMI

https://shop.thestreamin...bolt-3-expansion-chassis

Thinking the same

it's best to rely on the number of lines for less risk.
2 x decklink duo 2 cards would be safer.
a 3rd decklink card (mini recorder hd or mini monitor hd) or duo 2 would work, but maybe not on all ports.

you can use several cards
the important thing is that they are 4x maximum

the speed of all connected video ports must not exceed the maximum speed of the Thunderbolt 3 port (40 gbps = 5 GB/s)
you can even add a 3rd card in 4x (or 2x or 1x)

in theory :
thunderbolt 3 (4x) = pcie 2.0 x4 + pcie 2.0 x4 + pcie 2.0 x2 = 5 GB/s

depending on resolution and framerate, you may not be able to use all the ports on the 3rd card.

examples:

if in 1080p60 4.2.0 8 bits, the throughput of each i/o is around 0.5 GB/s
the thunderbolt port can handle a maximum of 10 i/o

if in 1080p30 4.2.2 10 bits, the throughput of each i/o is around 0.25 GB/s
the thunderbolt port can handle a maximum of 20 i/o

it's all theory
it's in practice that you'll see the limits.

x4 cards are preferable

with a quad 2 (x8) it's like asking 8 cars with a quad 2 (x8) it's like asking 8 cars to arrive at the same time on a 4-lane highway
there will be an accident


dawlzer, above, shared his experience



Following the raw SDI speeds (I'm rounding off), with an installation with 3 x Duo 2 cards (= 12 sdi ports) on the Sonnet echo express IIIe

3G-SDI = 2.97 Gbps = 0.4 GB/s
12 SDI ports = 4.8 GB/s

HD-SDI = 1.45 Gbps = 0.2 GB/s
12 SDI ports = 0.2 x 12 = 2.4 GB/s

This means that for a Thunderbolt 3 port = 5 GB/s

with 3G-SDI, the maximum is 12 ports

in HD-SDI, we could add a 2nd Sonnet with 3 x duo 2 cards in daisy chain and get 24 SDI ports

All this is in theory
You'll have to check it out in practice, because it also depends on the configuration of the PC you're using.

the most important thing is the number of lanes, before the bandwidth
but try