Since Chrome’s very first release, performance has been one of Google’s top priorities. But Google is against a competing force: Web developers. The Web of today is a more-complex, bandwidth-intensive place than it was when Chrome was first released, which means that—although Internet connections and the browser itself are faster than they’ve ever been—slow pages remain an everyday occurrence.
Google engineers have been developing “Never Slow Mode” in a bid to counter this. Spotted at Chrome Story (via ZDNet), the new mode places tight limitations on Web content in an effort to make its performance more robust and predictable.
The exact design and rationale of Never Slow Mode aren’t public—the changelog for the feature mentions a design document but says it’s currently Google-internal. But taken together, that design and rationale will ensure that the browser’s main thread never has to do too much work and will never get too delayed. They will also ensure that only limited amounts of data are pulled down over the network. This should make the browser more responsive to user input, lighter on the network, and a bit less of a memory hog than it would otherwise be.
XMLHttpRequests to transfer data to and from servers. Synchronous requests tend to make pages feel slow, because the browser can’t run any other scripting while it’s waiting for the synchronous request to complete. Asynchronous
XMLHttpRequests remain supported, as these let the browser do other things while it’s waiting for the remote server to respond.
We’ve asked Google for comment but have heard nothing at the time of writing.