Blackmagic Forum

Hello,

I set up a new machine with Decklink 8k Pro, which is a great device (4x 4k-SDI bidirectional).

Now I want to install a decklink card in an older machine as a fallback machine, but it has only got a PCIe slot with 4 lanes available. DeckLink 8k Pro needs 8 lanes, so I should get a smaller DeckLink.

Just to be sure: There is no DeckLink with two indepentend 4k SDI connections two-way, so both can used as out and in that also uses a 4 lane PCIe connection? It would be ok by me if out and in connections were separate, so there is no need to have a single bi-directional connection.

So, the best I could achieve is either using DeckLink Studio 4K or DeckLink SDI 4K both with only one 4k SDI connection, correct? But can I use with DeckLink Studio 4K both connections (SDI and HDMI) simultaenously with 4K resolution?

Best regards
Floh

For single-channel DeckLink cards such as the DeckLink Studio 4K, only one of the video input ports is active at a time (you have to select whether to capture from the SDI or HDMI input in the Desktop Video Setup utility). On the output side of things, both video outputs (SDI and HDMI) are active simultaneously, but they are not independent, so both ports will carry the same video output signal.

Only multi-channel DeckLink cards allow for simultaneous capture of multiple independent video signals (or simultaneous playout of multiple independent video signals, depending on the card). The current DeckLink lineup includes the following multi-channel cards:

• DeckLink Duo 2: four HD channels up to 1080p60 (each configurable as input or output)
• DeckLink Quad 2: eight HD channels up to 1080p60 (each configurable as input or output)
• DeckLink 8K Pro: four 4K channels up to 2160p60 (each configurable as input or output)
• DeckLink Quad HDMI Recorder: four 4K channels up to 2160p60 (each port input only, no output)

Regarding the DeckLink 8K Pro, the physical interface of the card requires at least an x8 PCIe slot due to the width of the portion of the card that contains the electrical contacts (the card would also fit in an x16 PCIe slot). From a bandwidth perspective, 8-lane PCIe 3.0 has a bandwidth of around 63 Gbps which is sufficient for 4 channels x 12Gbps SDI (48 Gbps). Presumably if you use fewer video channels of the card (2 instead of 4) or lower resolution video (6G SDI up to 2160p30 resolution), then this would reduce the PCIe bandwidth used by the card by half (to 4-lane PCIe 3.0 levels). This may be relevant if using the card in a system that has an x8 or x16 physical PCIe slot, to which fewer electrical PCIe lanes have been allocated by the motherboard.

Note that there have been several revisions of the PCIe standards. So PCIe 2.0 has less bandwidth per PCIe lane than PCIe 3.0, while PCIe 4.0 has more bandwidth per lane. Which means that the width of the PCIe slot alone doesn't reveal that much about the amount of bandwidth available:
https://www.cgdirector.com/guide-to-pcie-lanes/

Hello Dave,

thank you for your detailed reply with a lot of informations.

How do I know if one DeckLink Card has single or multi channel?

I'm already familiar with PCIe lanes, that is why I know my old machine (ASUS Maximus VIII Extreme) has 4 lanes (3gen) available. Yes I know there is a 8 lane slot, but it's shared with the GPU-Slot and I want avoid sharing lanes so I keep GPU running with x16. Sorry, I forgot to mention that my board has 3-gen PCIe slots. But thank you for taking time for explaining.

Interesting..., you're telling me that DeckLink 8K Pro still would work with 4 lane slot (I mean 16x physical, but 4x electric) with fewer video channels... this actually would be a preferred solution for me since I'd running 4x 4K/30p on my old machine. The machine just for in case of fallback situation.

You're sure it works? I thought DeckLink 8K Pro won't work on 4-lane slot.

Do anyone have experience using DeckLink 8K Pro on 4lane-slot?

Best regards
Floh

Florian : Dont forget about CPU .. GPU use 16 lanes .. And most CPUs have only 16 lanes .. i9 cpus have 20 lanes .. Only X procesor have enough lanes .. We have 4 computers with Decklink 8K cards in out TV .. And we get random restarts .. At beggining it was daily .. After some updates (bios, drivers, ...) its mostly stable .. But We use only 2160p50 input and utput .. 2 streams ..

Hello Roman,

Roman Pytkin Pekarek wrote:Florian : Dont forget about CPU .. GPU use 16 lanes ..

...and don't forget the chipset.

But thank you for reminding. I already know that and the CPU of older machine actually has only 16 PCIe lanes. My new machines have both CPUs with 48 PCIe lanes, there are Intel 10980XE with X299X chipset. But that is another story.

I see I should write more details of my old machine... didn't know its needed here...

In the old machine there is a ASUS Maximus VIII Extreme installed which has a Z170 chipset. It provides 20 PCIe lanes. I know... there are built in devices like USB, SATA, Network, ... and they all uses PCIe lanes of the chipset.
The first three 16x-slots are connected directly to CPU. Its an Intel 6700K with 16 PCIe lanes. That is why I wrote earlier, that I don't want share the lanes by using the 8 lane slot, which would bring down the connection for GPU from 16x to 8x. In the first slot there is a Nvidia 980 TI installed. Slots #2 and #3 are empty. The last slot, which has 4 lanes is connected to Z170 and is fully available if I disable SATA #5 & #6. These both SATA connections are disabled in my case because I only use SATA #1 & #2.

I already know, the connection to CPU is faster than to chipset because of latency over the chipset and bottleneck between chipset and CPU. The chipset Z170 uses DMI 3.0 which means the speed between the chipset and cpu is roughly equivalent to a 4 lane PCIe connection (so, roughly 33.8 Gb/s).

So, now there is detailed reason why I opened this thread and I asked about a suitable DeckLink for 4 lanes gen3 PCIe. And to be able to using up to 4x SDI 6G at the same time would be great for me, if possible... but 4x SDI 3G is sufficient.

Roman Pytkin Pekarek wrote:We have 4 computers with Decklink 8K cards in out TV .. And we get random restarts .. At beggining it was daily .. After some updates (bios, drivers, ...) its mostly stable .. But We use only 2160p50 input and utput .. 2 streams ..

Are these DeckLink 8K Pro Cards, built in in your 4 computers, inserted in a 4 lane PCIe slot*?

*) By 4 lane PCIe slot I mean electric 4 lane (physically it may be x8 or x16).

Best regards
Floh

DeckLink Duo 2 will do 4x 3G-SDI.

Hello Asgeir, thanx for your posting.

Asgeir Hustad wrote:DeckLink Duo 2 will do 4x 3G-SDI.

Sure but I want a DeckLink which offers 4K resolutions.

Best regards
Floh

floh79 wrote:

Roman Pytkin Pekarek wrote:We have 4 computers with Decklink 8K cards in out TV .. And we get random restarts .. At beggining it was daily .. After some updates (bios, drivers, ...) its mostly stable .. But We use only 2160p50 input and utput .. 2 streams ..

Are these DeckLink 8K Pro Cards, built in in your 4 computers, inserted in a 4 lane PCIe slot*?

We use ASUS TUF GAMING Z590-PLUS mainboards ..

It have 16x slot where is GPU
And 16x slot (with 4x mode) , where is Decklink 8k

Roman Pytkin Pekarek wrote:We use ASUS TUF GAMING Z590-PLUS mainboards ..

It have 16x slot where is GPU
And 16x slot (with 4x mode) , where is Decklink 8k

Great. Thank you very much, this is exactly the Information I wanted to know. So it also works with 2 stream 2160p50 input at same time? I ask that because DMI 3.0 is full duplex and 1 in and 1 out should be fine, but 2 out or 2 in... it may be bottlenecked, depending on the usage of other devices connected with the chipset.

Best regards
Floh

Yes .. It is used for playout .. Normalny play 2160p50 files and switch for 2160p50 input , for live broadcast from studio ..

Great, thank you.

@BlackMagicDesign Team: Seriously, this forum needs "like" button!

floh79 wrote:Hello Roman,
My new machines have both CPUs with 48 PCIe lanes, there are Intel 10980XE with X299X chipset. But that is another story.

Would be interested to hear that story and your experience with that system! I’m looking to build a system with the same CPU and motherboard chipset, with 2x decklink 8K Pros.

Annoying the 13th gen only have 20 PCIe lanes but the 10th gen have 48!