The Elgato footage takes up quite a bit of space and takes some power to render. So if your computer has a decent graphics card and amount of harddrive space free then It shouldn't be a problem for you.

have just realized i rambled on about mainly rendering, but it should still help out

for editing/rendering, you dont 100% need a high end PC, but it helps, lots.

You'll need a fair amount of Hard Drive space, as recording at 1080 or even 720 with that elgato will produce large video files.

As far as requirements to simply record, i can't imagine it being to high, providing your PC is somewhat modern.

You need a decent CPU, anything like a recent i3/i5/i7 would be fine, but the better the CPU the faster you'll render stuff, unless you're using GPU acceleration, in which case your graphics card will be doing the rendering.

As far as i know, RAM makes editing nicer, it certainly helps previewing stuff, im unsure how much it helps rendering, but im certain it does.

You'll also need decent cooling, as rendering pegs your CPU/GPU at 100% for potentially quite a while, so its going to get toasty. Something like a laptop would probably get too hot and start thermal throttling (slows itself down in order to cool down)

If you need help with anything feel free to just message us, i should be knowledgeable enough to help!