Pep Guardiola made the somewhat surprising decision to name what was essentially his strongest possible XI, and its superior quality was telling from the start as it raced into a 2-0 lead.
Silva opened the scoring with a gorgeous volley and swiftly doubled City's advantage to cap off a fine move in the 15th minute, before Phil Foden effectively killed off any hopes of a Birmingham comeback before the interval.
City was less deadly in the second period as it failed to add to its lead, but it mattered little as it had no difficulty seeing out a comfortable victory.
Aitor Karanka and Birmingham will have been braced for a difficult day after seeing the line-up chosen by Guardiola, though nothing could have prepared it for the host's start.
Silva displayed remarkable technique to make it 1-0 as he unleashed a stunning volley just inside the box to punish a poor clearance, picking out the top-left corner.
He soon got a second with a simple close-range finish, guiding home Kevin De Bruyne's cutback after the Belgian had been well spotted by Riyad Mahrez.
City found its stride again after something of a lull, and Foden increased the lead just past the half-hour mark, rifling into the bottom-right corner from 20 yards after being picked out by Mahrez.
The host withdrew De Bruyne, Joao Cancelo and Ruben Dias at half-time, with youngsters Felix Nmecha and Taylor Harwood-Bellis entering alongside John Stones.
City remained dominant and thought it had a fourth goal just past the hour, only for VAR to confirm Mahrez had strayed offside when latching on to Foden's pass.
Silva passed up the chance to complete his hat-trick as he dragged wide when the ball fell kindly for him, and that proved to be his final opportunity as City settled for a three-goal victory.