[Geoff Chown]

WiFi is your friend. OBS can accept WiFi streams from pretty much any cam that sends them. There’s latency to compensate for, and you’ll probably need two WiFi routers to accommodate 4 cams, but it’s way cheaper than an ATEM. So far I haven’t found a way to stream from iPhones without paying for a $16 app, meanwhile LiveDroid works great and is totally free.

[Geoff Chown]

Key aspects are having an SSD boot drive and as many CPU cores as you can afford. I looked into this when I started with my relatively ancient Dell Latitude 6410, but it’s holding up fine because the i7-520M is a hyperthreaded dual core (4 logical cores) and I put an SSD boot drive in it back when I bought it for $100 5 years ago. It’s handling 4x 720p video streams and a few VST’s on the audio at about 40% CPU.

I wouldn’t recommend getting something as frugal as mine, but I’d definitely recommend bleeding edge used corporate/government laptops from the likes of Dell or Lenovo because they’re built tough and generally more serviceable, and of course budget for a backup. You should definitely get a hyperthreaded quad core CPU (8 logical cores), which includes some more recent i5’s as well as i7’s.

If you’re thinking new on a tight budget, they tend to have crappy fans that die and are buried under the motherboard, near impossible to replace. Run them hard, they die hard.