With the imminent release of Firefox 3 and Opera 9.5 being finalized this week, Lifehacker decided it was a good time to run the browsers head to head to see which was the fastest and least resource intensive. The testing system was a 2GHz 2GB Vista machine. The timing system used wasn’t directly hooked to the browser, so tests were repeated multiple times to improve accuracy. The cold start winner was Opera, but most browsers opened in about a second if they had been run recently. Safari did well loading content in multiple tabs at the same time, probably due to its short render times for JavaScript and CSS. The final test was memory usage; we’re sure many people will be happy to know that Firefox 3 RC3 only used 66% of the RAM required by the other three browsers.