Unfortunately for Chrome users that want an even more secure browsing experience, a new feature introduced in Chrome 63 for the desktop will ratchet up memory usage even higher. The feature, called Site Isolation, uses a strict policy that relegates individual websites to their own separate process.
"When you enable site isolation, content for each open website in the Chrome browser is always rendered in a dedicated process, isolated from other sites," writes Google in a support document describing the feature. "This creates an additional security boundary between websites."
This is a further extension of Google Chrome's default behavior, which typically uses one process per tab. However, certain situations mean that related tabs can share a process, and this is especially true when a large number of tabs are open (in this case, tab/process sharing is even more prevalent). That means a website crash or security incident could possibly knock out multiple tabs.
Site Isolation gives users better granular control to avoid situations like this with a dedicated rendering process, isolating sites from each other. The feature can either be turned on for all websites, or it can be turned on for a specific website (or group of websites).
Google is not enabling this feature by default, which is probably a good thing. Google says that turning on Site Isolation will result in a 10 to 20 percent increase in memory usage, which is a heavy price to pay for an already resource-intensive browser.