This guide was over a year in the making since Blackmagic took 360 days to reply to my support request. That said, let’s see if the DeckLink Quad HDMI Recorder knows how to Linux.
Grocery list:
DeckLink Quad HDMI Recorder
SIIG 1×2 Port HDMI 2.0 Splitter 4K
1. Desktop Video 12.1 only works with kernel version 5.10 and lower. You can check your kernel version by running the following command in a terminal.
uname -a
2. Download the latest version of Desktop Video from BlackMagic.
3. Install the required packages for compiling the Blackmagic kernel module. This example is for Debian / Ubuntu / PopOS.
sudo apt install build-essential linux-headers-$(uname -r)
4. Decompress the Blackmagic driver.
tar -xf Blackmagic_Desktop_Video_Linux_12.1.tar
5. Navigate to /Blackmagic_Desktop_Video_Linux_12.1/deb/x86_64 and install the packages using apt.
sudo apt install ./*.deb
6. Smash that reboot button, fam.
Note: If / when you perform a firmware update remember to power down the system completely.
7. Add the Decklink Quad to OBS by adding a Blackmagic Device to your OBS sources.
8. You will now be able to configure your device from the properties window.
9. For my brothers and sisters running Thread Ripper / Epyc. You will need to add amd_iommu=off to your grub config. This prevents the card from dropping frames.
Note: Don’t forget to update initramfs.
sudo update-initramfs -u
Verdict:
I really want to go on a rant about how Blackmagic tech support jerked me around for a month, had me RMA the card (at my expense), and told me nothing was wrong. Emailing Blackmagic developer support was a shot in the dark and while they were able to resolve the issue, it took 360 days.
At the end of the day the DeckLink Quad HDMI Recorder knows how to Linux. It’s taken a few years to hammer out the bugs but now it does everything it claims on the tin. More importantly it’s the only 4K quad in this price range.
Blackmagic DeckLink Quad HDMI

DeckLink Quad HDMI Recorder is a high performance PCIe card that lets you capture from 4 different HDMI sources.
Pros
4X 1080p capture
4X 2160p capture
Low noise.
Relatively inexpensive.
Cons
Blackmagic support.
Runs hot.
DSLR compatibility can be iffy.
Can't be used as a webcam.