How do I launch CS:GO FPS benchmark?

Launching the CS:GO FPS benchmark is pretty simple! First, you'll need to subscribe to the 'FPS Benchmark' map in the Steam Workshop. Once it's added to your game, fire up CS:GO, click on 'Play>Offline with Bots,' and select the 'Workshop' tab. Find the 'FPS Benchmark' map, choose 'No bots,' and hit start. When the map loads, follow the instructions displayed on the screen to begin the benchmark. It'll run through a test sequence, and afterwards, you'll see your FPS results displayed.

Honestly, the best way to check your FPS is to play the actual game. Real conditions > benchmarks.