Phoronix published a review on the Benchmarks Show Firefox 57 Quantum Doing Well, But Chrome Largely Winning A quote from the article:

With the hype this week around Firefox Quantum Beta with its user-interface refinements and more noticeably the performance improvements, I decided to run some benchmarks on my end with a variety of tests comparing Firefox 52 ESR, Firefox 56 stable, Firefox 57 Quantum beta, and Chrome 60. Here are those web browser benchmark results from the Linux x86-64 desktop.

 Benchmarks Show Firefox 57 Quantum Doing Well, But Chrome Largely Winning @ Phoronix