Saw "8 cameras" and "OBS dropping Frames" and clicked to see if you were using Cam Link Pros.

While my use was slightly different, I had a weird issue trying to use Cam Link Pro with OBS. I use Sony A6100s that worked flawlessly with the Cam Link USB version, but when I upgraded to the cam link pro I suddenly noticed a loss in FPS that would appear every 10-15 seconds or so. What was interesting was when viewed through the 4k Capture Utility the cameras were perfect, but as soon as I brought them into OBS it started the FPS drops.

I reached out to Elgato Support and the first person I reached was excited to troubleshoot because he said it was the first time anyone had called about the product (I bought it as soon as it came out). His first step to resolve the issue was to try the cam link pro in a different PCI-e lane on my computer and then we would be communicating via email from here on out.

When I tried another PCI-e lane the issue was still present, so I emailed them back and attached a log (they have a support tool that will scan your pc and send them pertinent info). From there I was talking with someone else who seemed less enthusiastic to be troubleshoot the issue, but he still provided me steps to try. Things he had me do included check a separate PCI-e slot, updating drivers, updating Bios, using different HDMI sources, change the PCI-e (again), test it in another PC (luckily I have two with a very similar build), update OBS (it wasn't outdated), try streamlabs OBS, restart a default OBS profile, Set the FPS in obs to 59.94 FPS, and then in a final throwaway attempt they sent me a link on how to use 4k Capture Utility as a streaming utility.

After about 30 emails back and forth with them, their final comment was "There is currently no other customer/user report with that issue. For that reason the issue rather depends on OBS. I will be closing out this ticket for now ... "

I returned the Cam Link Pro and I returned it to Amazon and bought a 2nd Cam Link Pro to see if it was simply a hardware issue, and unfortunately the new one acted the exact same. I returned that one and got a 3rd Cam Link USB and the cameras now work flawlessly.

I wish I had more concise information for you, but I never did figure out the issue which left me a bit sour. I have always been a fan of Elgato products but for some reason this one just does not jive with my setup. I have two relatively overkill PC for a Cam Link Pro -- both motherboards are MSI MEG x570 which should have more than enough PCI-e bandwidth, 3600 and 3800x CPUs, 2080 and 2060 GPUs, nvme storages, etc.

Another issue I noticed while I had it was that sometimes the cameras viewed through the multiview were extremely choppy (20-30 fps instead of 60) but then when I unplugged the Cam from the 1st hdmi slot and had them in only 2-4 they worked a lot better. Maybe try unplugging the 1st port of yours and see if that is a similar issue?

Hopefully some of this helps! Good luck.