Start times are recorded right after a fresh boot (cold) and again after the browser has already been launched (hot). We time both a single home tab and an eight-tab group. Yahoo! serves as the test page for our single-tab tests, while pages from About, Amazon, Ask, craigslist, Google, LinkedIn, and Wikipedia round out the test pages of the eight-tab measurement. All test pages are hosted on our local Web server and cached in the Web browsers.
The start time composite score is the geometric mean of the hot and cold times for the single-tab and eight-tab tests.
Google Chrome takes a slight lead over Safari on Apple's own operating system, at two and 2.2 seconds (respectively). Firefox places third with just under 2.5 seconds, followed by Opera at three seconds.
All of the Windows 7 times are significantly lower than OS X, with Chrome again taking the lead at just 0.8 seconds. This time, Chrome is followed by Opera at just under one second. Internet Explorer is in third place at just over 1.2 seconds with Firefox placing fourth, mere tenths of a second behind IE9.
The charts below contain results for cold and hot single-tab start times, followed by the cold and hot eight-tab times.
Chrome is the clear winner at start time, with the only exception being a longer single-tab cold start than the other competitors. Firefox and IE9 also display irregularities. Mozilla's browser has a slight advantage starting with a single-tab cold versus hot, while IE9 takes an incredible amount of time to open a single tab cold versus any other situation.