Google Chrome on Windows was criticized many times for its enormous RAM usage and crashes when there were a lot tabs open. Moreover Google never admitted the problem and continued to improve other aspects of the browser not taking into account the performance, and making only small changes and optimizations that weren't enough. However, with the recent releases of Chrome 53 for 64-bit Windows systems and Chrome 54 for 32-bit Windows, Google claims to have finally improved its performance significantly.
This was made possible by implementing the Profile Guided Optimization (PGO) mechanism available in the C++ compiler used on Windows. The secret behind it is that the browser with PGO enabled will track what features and API functions are used the most and after analyzing this data, the compiled version will optimize the code behind the most used features making it faster.
According to Google, using Microsoft's GPO has improved the startup time by 16.8% while overall page loading speed improved by 14.8%. The New Tab also loads 5.9% faster in the new versions.