STABLE version -- 5.0.1002.354

[Serg]

Useful:

Process-per-site-instance: Chromium creates a renderer process for each instance of a site the user visits. This ensures that pages from different sites are rendered independently, and that separate visits to the same site are also isolated from each other. Thus, failures (e.g., renderer crashes) or heavy resource usage in one instance of a site will not affect the rest of the browser. This model is based on both the origin of the content and relationships between tabs that might script each other. As a result, two tabs may display pages that are rendered in the same process, while navigating to a cross-site page in a given tab may switch the tab's rendering process.

Process-per-site:Chromium also supports a process model that isolates different sites from each other, but groups all instances of the same site into the same process. This model is based on the origin of the content and not the relationships between tabs.

One of the most obvious difference is that under Process-per-site mode, it makes sure that each site uses no more than one process, while in Process-per-site-instance (which is the default mode) one sites could have more than one processes.