Here's a free extension that will save memory and CPU cycles in Google's Chrome browser by putting inactive tabs to sleep.
1. Go to the Tab Hibernation page.
2. Click the Add to Chrome button to install Tab Hibernation.
Your tabs will not be lost, one click will restore them so you can begin using those windows again in Chrome. Tab Hibernation can make your computer run faster by stopping Chrome tabs from consuming too many system resources.
Read more: Ghacks