Red Dead Redemption 2 is soon coming to PC, and we've learned about the spec requirements that you will need to be able to run it. Keep in mind that these are the minimum requirements to actually play the game, so you probably won't get a smooth experience with it if you can barely run it.
Anyway, here are the minimum specs needed to run Red Dead Redemption 2:
OS: Win 7 64
Processor: Intel Core i5-3570 3.4GHz / AMD FX-6350
Graphics: AMD Radeon R9 285 2GB or NVIDIA GeForce GTX 960 2GB
System Memory: 8 GB RAM
Storage: 100 GB Hard drive space
DirectX 11 Compatible Graphics Card.