Blackmagic SDI Cards are pants. Prove me wrong!

[techiejay]

Hi All,

Has anybody in the known universe managed to get smooth video from a Blackmagic capture card?

Latency I don't mind, I'm expecting a few frames here and there, but the choppy, stuttering capture is just a dealbreaker.

I know it's not Resolume (because BMD's own app shows the same) and I know it's not my rig, because I've replaced every part except the capture card (so many changes in fact that I've had to re-activate Windows)

CPU, Memory, Disk and GPU are all idling by easily, but the video still isn't smooth. What should I use instead? Or is there some secret 'don't be shit' setting that I've missed somewhere...!

Ta muchly for any help

Jay

[Oaktown]

Can you give more information about your system?

[techiejay]

Sure,

Intel i7-8700 3.2Ghz
MSI Mortar Motherboard
32GB RAM
480Gb Samsung SSD
GeForce 660ti GPU
Win10 Pro

BMD Decklink Mini Recorder PCIe

CPU never gets above 20%, nor does RAM or GPU. Arena FPS never drops below 60, even with multiple layers and multiple loops triggered alongside the cam input.

Starting to lose the will a bit with it here

Jay

[dirtyjohn_lv]

You’re possibly bottle necking somewhere

The 8700 only supports 16 PCIE lanes
Up to 1x16, 2x8, 1x8+2x4 (From Intel site)

The 660ti is an x16 card, but runs at x8 because you have the BMD capture installed (x4 design)

Depending on how your SSD is connected (M2 or SATA) could be causing issues (M2 generally uses PCIE bus)

[Oaktown]

@dirtyjohn_lv, that was my thougth as well but the BMD card is only PCI Express 1 lane so unless there are other things on the MB that are sucking up bandwidth, that might not be the issue.

@techiejay, do you have any other expansion boards on your MB? Also, what firmware is your BMD card on?

[techiejay]

Howdi both,

Thanks for coming back to me. SSD is definitely on SATA, so no issues there.

Only other card in the machine is a BMD Mini Monitor (SDI out) but I’ve never used it, so this can easily be removed.

Not sure on firmware version but I can certainly check this after tonight’s show.

Jay

[Oaktown]

I would upgrade to the latest version available on the blackmagic website

[techiejay]

So, I’m back!

Decklink Mini Recorder has been updated to the very latest firmware (and latest Desktop Video software) and the Mini Monitor has been removed.

I’ve also applied the latest Resolume update.

Result is still the same

In fact it’s even more pronounced this weekend because I’ve split my ATEM output - one feed goes direct to some projectors, the other feed goes to Resolume to run the Tron.

I can only describe the look as when you switch a camera from 50i to 25p - it’s not unusable, the movement is just nowhere near as fluid.

Thanks all for your help so far!

Jay

[AlexanderH]

Did you check your Signal with Decklink Studio Monitor to make sure your sdi cable is ok? I had trouble with a new cable and changing the cable did remove all trouble...

[techiejay]

Did you check your Signal with Decklink Studio Monitor to make sure your sdi cable is ok? I had trouble with a new cable and changing the cable did remove all trouble...

I did indeed, it's the same with every cable

Jay