Retina MacBook Pro owners who have been frustrated at slow Safari performance may find some relief in the recent WebKit nightly builds. The discovery was originally dug up by a MacRumors forum post and tested by AnandTech on Tuesday, showing a significant increase in frame rates when scrolling through certain sites, such as Facebook.

AnandTech put one of the recent builds to the test on a 13-inch MacBook Pro with retina display running Mountain Lion at 1440x900 (AnandTech used version r135516, though the most recent build as of publication is version r136460). Using Quartz Debug to look at the differences in frame rate, the site saw the average of sites like Facebook more than double, from an average of around 20fps to around ~47fps. But this "fix" only applies to media-heavy sites that previously caused the MacBook Pro to choke up—when testing on sites that otherwise performed fine in Safari on the retina MacBook Pro, performance remained roughly the same.

According to the MacRumors forum thread, Apple plans to eventually release a full version of Safari with this level of optimization, so if you're wary of running prerelease builds of WebKit, you may not have to wait long. But if you're a retina MacBook Pro user whose blood pressure ticks up every time Safari gets laggy, the nightly build could offer you sweet, sweet relief until the next major Safari release comes down the pipeline.