I assume all graphics data is sent from the tab sub-processes to the main process (Chrome and similar in IE9-11). Multiprocess is different in Firefox, to get full multiprocess (per tab) we maybe have to wait a bit longer, for a Servo based browser.
Launching processes is a bit expensive especially on WinNT series (up to Win10), but ultimately it's the way to go ("sandbox" = sub-processes with minimum permissions) - even Servo with its Rust language use it as certain parts like the JavaScript engine are still C/C++ based (come from Firefox/gecko) for the near future and can crash.
Launching processes is a bit expensive especially on WinNT series (up to Win10), but ultimately it's the way to go ("sandbox" = sub-processes with minimum permissions) - even Servo with its Rust language use it as certain parts like the JavaScript engine are still C/C++ based (come from Firefox/gecko) for the near future and can crash.