UltraStudio DeckLink Thunderbolt enclosure

Hello,

I'm currently using Sonnet's Thunderbolt 3 enclosures to connect DeckLink cards to a Thunderbolt enabled PC (an Intel NUC 11 Enthusiast). While it works ok there are a few problems:

• they are designed for much bigger cards and take a lot of space (especially the Echo III RackMount version)
• using the Echo III RackMount version, I get ~30 frames of latency as soon as I play more than one 2160p50 video (using the Echo SE III and SE I, I can play up to 3 2160p50 videos with 4 frames of latency, and it also jumps to 30 frames when I play a fourth one). See https://forum.blackmagicdesign.com/viewtopic.php?f=12&t=160403

It would be amazing I BlackMagic could do an UltraStudio (4K or HD if possible) Mini sized, daisy chainable Thunderbolt enclosure for the DeckLink cards!

Daisy chainable, 12G versions of the UltraStudio Recorder/Monitor 3G could do as well (and please, make the future MicroConverters 44 mm high rather than 45 and 45.8 so that we can easilly rack them).

Keep up the good work

you're looking for a half-lengh case, such as

https://www.bhphotovideo.com/c/product/ ... _se_i.html

One thing worth noting about Thunderbolt 3 and Thunderbolt 4 is that even though these ports are theoretically capable of 40 Gbps of bandwidth, the data transfer channel uses a PCI Express 3.0 x4 interface which is limited to around 32 Gbps of bandwidth. To fully saturate the 40 Gbps interface of a Thunderbolt 3 or 4 port would require something like DisplayPort output (as that is separate from the 32 Gbps data channel).

This data transfer bandwidth limitation has implications when daisy chaining multiple Thunderbolt devices or when using a multi-slot PCIe Thunderbolt enclosure. Because effectively all of those PCIe slots (or devices) connected to that Thunderbolt port are sharing the same 32 Gbps PCIe 3.0 x4 interface into the computer. And in fact even a single PCIe card could exceed the available bandwidth if it uses a PCIe 3.0 x8 or x16 interface and actually uses that much bandwidth.

For a lot of PCIe cards, this bandwidth sharing may not be a huge issue (which is why manufacturers put x8 or x16 slots in those enclosures to begin with). Things may slow down if there is bandwidth contention, but storage, network, graphics will often still work fine, just perhaps not as fast as if more bandwidth were available. For video capture or playout cards though, where you need frames to be processed at a certain rate, these types of bandwidth limitations can be problematic.

And with Thunderbolt 3 specifically, things are sometimes even a bit worse than this, because the Thunderbolt 3 specifications allow computer hardware manufacturers to use either a PCIe 3.0 x4 (32 Gbps) or a PCIe 3.0 x2 (16 Gbps) interface to the port. And some laptop vendors (including Dell and others) opted for the slower PCIe x2 interface for their Thunderbolt 3 ports on some models.

With Thunderbolt 4, a PCIe 3.0 x4 interface (32 Gbps) to the port was made required rather than just being optional as it was with Thunderbolt 3.

So especially with multiple streams of higher frame rate 4K 50fps/60fps video which is 12 around Gbps at the SDI interface (but may be a bit less when going between the capture card and computer, depending on the frame and pixel format used), it's certainly possible to exceed the 32Gbps bandwidth of the Thunderbolt data channel.

Some additional background on Thunderbolt interface and bandwidth in this tech brief:
https://www.thunderbolttechnology.net/s ... _FINAL.pdf

you're looking for a half-lengh case, such as https://www.bhphotovideo.com/c/product/ ... _se_i.html

I also have the SE I, but that's still much bigger than the UltraStudio 4K / HD, and it's not rackable.

One thing worth noting about Thunderbolt 3 and Thunderbolt 4 is that even though these ports are theoretically capable of 40 Gbps of bandwidth, the data transfer channel uses a PCI Express 3.0 x4 interface which is limited to around 32 Gbps of bandwidth. To fully saturate the 40 Gbps interface of a Thunderbolt 3 or 4 port would require something like DisplayPort output (as that is separate from the 32 Gbps data channel).

This data transfer bandwidth limitation has implications when daisy chaining multiple Thunderbolt devices or when using a multi-slot PCIe Thunderbolt enclosure. Because effectively all of those PCIe slots (or devices) connected to that Thunderbolt port are sharing the same 32 Gbps PCIe 3.0 x4 interface into the computer. And in fact even a single PCIe card could exceed the available bandwidth if it uses a PCIe 3.0 x8 or x16 interface and actually uses that much bandwidth.

For a lot of PCIe cards, this bandwidth sharing may not be a huge issue (which is why manufacturers put x8 or x16 slots in those enclosures to begin with). Things may slow down if there is bandwidth contention, but storage, network, graphics will often still work fine, just perhaps not as fast as if more bandwidth were available. For video capture or playout cards though, where you need frames to be processed at a certain rate, these types of bandwidth limitations can be problematic.

Well even 32 Gbps instead of 40 is a lot. Currently with one Sonnet's Echo III hosting two DeckLink 8K Pro & one DeckLink Quad 2 connected to an Intel NUC 11 Enthusiast I can simultaneously:

• generate & output two 12G fill & key signals (each showing an OpenGL scene), using the 4 slots of the 1st 8K Pro
• h265 encode and record two 6G streams, using 2 slots of the 2nd 8K Pro
• read two 12G streams (used to take snapshots upon demand), using the 2 other slots of the 2nd 8K Pro
• read several PAL streams (I tried 4 IIRC), using the Quad 2

I get 4 frames of latency when using the Echo III Desktop, and ~30 with the Echo III Rackmount (which is a shame since I have to use the latter in production. Sonnet's support has not been able to give a solution . But since it works with the desktop version the Thunderbolt is able to do that).
Being able to do that with 3 daisy-chained Teranex Mini - like enclosures would be amazing. The Echo III is really nice but designed for much bigger cards.

And with Thunderbolt 3 specifically, things are sometimes even a bit worse than this, because the Thunderbolt 3 specifications allow computer hardware manufacturers to use either a PCIe 3.0 x4 (32 Gbps) or a PCIe 3.0 x2 (16 Gbps) interface to the port. And some laptop vendors (including Dell and others) opted for the slower PCIe x2 interface for their Thunderbolt 3 ports on some models.

With Thunderbolt 4, a PCIe 3.0 x4 interface (32 Gbps) to the port was made required rather than just being optional as it was with Thunderbolt 3.

I didn't know that, thanks! Our Intel NUC 11 Enthusiast has two Thunderbolt 4 ports though.

So especially with multiple streams of higher frame rate 4K 50fps/60fps video which is 12 around Gbps at the SDI interface (but may be a bit less when going between the capture card and computer, depending on the frame and pixel format used), it's certainly possible to exceed the 32Gbps bandwidth of the Thunderbolt data channel.

There's much less than 12 Gbps going between the card and the computer for a 12G SDI stream, otherwise I wouldn't be able to do the above. It's hard to know what is possible to do without testing.

Some additional background on Thunderbolt interface and bandwidth in this tech brief:
https://www.thunderbolttechnology.net/s ... _FINAL.pdf

Very interesting, thanks! But again, we can't compare SDI rates with Thunderbolt bandwidth.