In practice, Microsoft says the new mode will improve speed and responsiveness overall while "optimising" the use of battery, CPU, and RAM. Apparently, the mode may adjust based on your browsing habits too.

"Performance mode helps you optimise speed, responsiveness, memory, CPU and battery usage. Performance improvements might vary depending on your individual specifications and browser habits."

Vole notes that the "Sleeping Tabs" feature in Edge will be locked to five minutes when performance mode is turned on. "Sleeping Tabs" freezes a tab that's left open in the background, saving resources when it's not actively being used. Performance Mode is rolling out now in version 91.0.856.0, available in the Canary channel. The toggle is available in the "System" section of the settings menu.