You don't need two PC's to stream to be a successful streamer, but it does have 2 big advantages:
Aladdin has been streaming since November 2016. He's an Ex-Professonal BR and H1Z1 Player.
For gaming, Aladdin uses a Intel Core i7-8700k CPU with a MSI GeForce GTX 1080 Ti GPU. He uses a ASUS PRIME Z270-A motherboard. Aladdin uses CORSAIR Vengeance Lpx 16GB memory and a Samsung 960 EVO 1TB SSD for storage.
For streaming, Aladdin uses a Intel Core i7-6700K CPU with a MSI GeForce GTX 1080 GPU. He uses a MSI Z170A XPOWER GAMING TITANIUM EDITION motherboard. Aladdin uses Crucial Ballistix Sport 16GB memory.