2 DS Cap Cards Work Fine, But 4 DS Cap Cards Flicker

[BasilSoFresh]

Hey all, I've had 2 loopy cap cards for a while now and things have been working fine. I just got another 2 cap cards and well, the infamous flickering issue is happening now. I can only run 2 cap cards at a time.

I tried plugging them into different USB hubs and tried having OBS and YouTube videos open to no avail. Has anyone run into this issue?

[leo60228]

With the way USB works, multiple USB ports using the same controller will share the 480Mbps supported by USB 2. It's likely that this isn't enough for four capture cards. If you're lucky, your device might have multiple controllers and a specific combination of ports will work, but otherwise you'll need a separate controller (likely on a PCIe card).
If you have a laptop, I'm not aware of any good solutions. If your laptop supports Thunderbolt, you could put a USB card in an eGPU dock, but this will be very expensive.
You could also use what's called a "transaction translator" that turns a USB 2 device into a USB 3 one (like those based on the VIA Labs VL671 chip), allowing it to use the much more plentiful 5-10 Gbps available there. These are very niche, have compatibility issues, and I'm not aware of any being sold as a readily available standalone product.

[BasilSoFresh]

With the way USB works, multiple USB ports using the same controller will share the 480Mbps supported by USB 2. It's likely that this isn't enough for four capture cards. If you're lucky, your device might have multiple controllers and a specific combination of ports will work, but otherwise you'll need a separate controller (likely on a PCIe card).
If you have a laptop, I'm not aware of any good solutions. If your laptop supports Thunderbolt, you could put a USB card in an eGPU dock, but this will be very expensive.
You could also use what's called a "transaction translator" that turns a USB 2 device into a USB 3 one (like those based on the VIA Labs VL671 chip), allowing it to use the much more plentiful 5-10 Gbps available there. These are very niche, have compatibility issues, and I'm not aware of any being sold as a readily available standalone product.

One thing worth noting is it's a desktop and not a laptop, but I just bought a PCI-E card that's SATA powered, and I tried plugging in one of the DSes alone and the only thing I hear right now is the USB plug-in sound being spammed. I plugged my mouse in just to test and see if it's the PCI card, but my mouse works fine.