…from: http://www.macrumors.com/2015/06/12/chrome-os-x-performance-improvements-saf...

Google Improving Chrome for OS X Performance to Better Rival Safari Friday June 12, 2015 4:52 AM PDT by Joe Rossignol

Google senior software engineer Peter Kasting this week announcedhttps://plus.google.com/+PeterKasting/posts/GpL63A1K2TF that his team has been working to address Chrome for OS X battery hog complaints by improving the performance of the browser on Mac, especially in areas where Safari appears to do better (via iPhoneHackshttp://www.iphonehacks.com/2015/06/google-working-improvements-address-chromes-battery-hog-complaints-mac.html).

Chrome for OS X has received multiple under the hood improvements that should result in faster performance and longer battery life while browsing. The browser, for example, now requires significantly less CPU usage when loading the Google search results page and various other websites.

The other technical changes to Chrome for OS X are outlined as follows: "The team has been working on addressing this; here are some cases that have recently been improved on trunk:

http://crbug.com/460102

Before: Renderers for background tabs had the same priority as for foreground tabs. Now: Renderers for background tabs get a lower priority, reducing idle wakeups on various perf test, in some cases by significant amounts (e.g. 50% on one test).

http://crbug.com/485371

Before: On a Google search results page, using Safari's user agent to get the same content that Safari would, Chrome incurs ~390 wakes over 30s and 0.3% CPU usage vs. Safari’s 120 wakes over 30s and 0.1% CPU usage. Now: 66% reduction in both timer firings and CPU use. Chrome is now incurring ~120 wakes over 30s and 0.1% CPU use, on par with Safari.

http://crbug.com/489936

Before: On capitalone.com, Chromium incurs ~1010 wakeups over 30s vs. Safari's ~490 wakes. Now: ~30% reduction in timer firings. Chrome is now incurring ~721 wakeups over 30s.

http://crbug.com/493350

Before: On amazon.com, Chromium incurs 768 wakups over 30s and consumes ~0.7% CPU vs. Safari's 312 wakes over 30s and ~0.1% CPU. Now: ~59% reduction in timer firings and ~70% reduction in CPU use. Chrome is now incurring ~316 wakeups over 30s, and 0.2% CPU use, on par with Safari at 312 wakes, and 0.1% CPU use." Many of the changes will first appear in Chromium before going live on Chrome for OS X.