How would I use one of these for recording?

Basically, it's an internal capture card that you would install into your computer rather than an external like an Elgato. By what I can tell on the site, it's a pass-through encoder, basically if you want to record PC games on it, you'll have to set up the capture card as if you're setting up a second screen.

But you would still have to use OBS to record, it would simply take most of the strain off of the rest of your PC and do a lot of the heavy lifting when it comes to recording gameplay.

I have this device. Here is how you can use it.

If you are using a game console or second computer you just input the hdmi into this card then out to your monitor. You would then use the provided software to record (best results) or use a secondary software to record (mixed results).

If you are using the same computer to record then you take the hdmi out of your graphics card, into this card. From there you output to your monitor. I would recommend only using the provided software to record in this configuration. The reason why is...this device is meant to handle most of the computer's load that would be used to record, but (in my findings) it only works with the provided software. I've tried OBS, Xsplit and other broadcasting/screen capture software and it just doesn't record as smooth. It's a very nice device, but you might be better off with an external usb3 device.

I'm not sure I could, in good conscience, recommend this product. It's very finicky, and very difficult to get to record properly using external software. If you're only going to use the Avermedia software, then it works great.

Hope this helps.