My PC specs are:
CPU I7-4790k 4.0Ghz
RAM Corsair CML16GX3M4A1600C9B Vengeance Low Profile 16GB (4x4GB)
GPU EVGA GTX 960 FTW 4GB
Motherboard Asus Z97-PRO Gamer S1150 ATX
Keyboard Havit (KB558CM)
Mouse Corsair Scimitar
OS Windows 10
However I also have a second computer which does all the recording, kind of like a dual streaming system but a little less complicated, in that I use an Elgato HD 60 Pro for the transfer of the image and sound.
However it's not got a big GPU just a Nvidia 580 GTX but the CPU is a I5-4690K 3.5 Ghz and about 2TB of hard drive space, it mostly just records or renders the videos, this one has 8GB RAM.
You can see a far more detailed streaming setup post here
http://www.bredishbunch.com/home/rggdales-streaming-setupIf I've left anything out that you want to know about just let me know