Google Chrome is one of the most popular Internet browsers in the world, but over time it has also been criticized for being a resource hog compared to alternative solutions. The good news is that Google is always working on improving Chrome in a variety of areas, including performance, and according to a new official blog post, Chrome is now up to 15% faster on Windows machines after the adoption of Microsoft’s Profile-Guided Optimization (PGO) technology added with the Chrome 53 update.
According to Google, following the Chrome 53 update and the inclusion of Microsoft’s Profile-Guided Optimization technology, new tab page load times are 14.8% faster, page load (time to first paint) is 5.9% quicker, and startup time is 16.8% faster. These improvements have taken place after Google implemented Microsoft’s PGO technology within Chrome, meaning that these new performance increases are available only on Windows-powered terminals. As for how PGO works, to begin with, Chrome has over a million functions in its source code, and according to Google “some [functions] are called frequently, while others are rarely used”. Microsoft’s PGO technology used data from runtime execution tracking functions that are most common to guide optimization, and to gather the data “the nightly build process now produces a special version of Chrome” which keeps tabs on how often functions are being utilized. Microsoft’s technology optimizes high-use functions to improve speed, while optimizing less-used functions “with smaller, though slightly slower code”. This results in a smaller code footprint overall, but Microsoft’s Profile-Guided Optimization technology also optimizes the memory location of the code by “moving rarely-used functions away from frequently-used ones” in memory, leading to CPU instruction cache optimization and an increase in overall performance. Other tricks used by PGO to improve performance include Conditional Branch Optimization, Dead Code Separation, Function Layout, Virtual Call Speculation, Register Allocation and a few other.
Microsoft’s PGO technologies, and therefore the aforementioned performance improvements, are part of Google Chrome 64-bit as of version 53. For 32-bit Chrome, PGO has been used as of version 54. Once again, it’s worth reminding that the overall 15% improvement in performance affects only Windows-powered machines, so Android users and / or Chromebook owners are out of luck.