Steel Beam vs Gable for Patio Cover?


I want to build a patio cover that spans 50’ x 12’ with no center posts, and is attached to the back of house. Does using a two-beam gable design at a low angle, such as 20 degrees, or even four sections like a barn roof, help offer the support needed to achieve that span on two posts rather than using steel beam?

Any insight would be appreciated.